2023 |
Kamruzzaman MD, Djenidi L, Antonia RA, 'Experimental study of two side-by-side decaying grid turbulent fields at different mean velocities', JOURNAL OF TURBULENCE, 24 (2023) [C1]
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Nova |
2023 |
Tang SL, Antonia RA, Djenidi L, 'The '-1' decay law for some small-scale quantities at large Péclet numbers and fixed Reynolds numbers', JOURNAL OF FLUID MECHANICS, 977 (2023) [C1]
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Nova |
2023 |
Tang SL, Antonia RA, 'Similarity for dissipation-scaled wall turbulence', Journal of Fluid Mechanics, 960 (2023) [C1]
In this paper, we put forward a hypothesis for turbulent kinetic energy, Reynolds stresses and scalar variance in wall-bounded turbulent flows, whereby these quantities, when norm... [more]
In this paper, we put forward a hypothesis for turbulent kinetic energy, Reynolds stresses and scalar variance in wall-bounded turbulent flows, whereby these quantities, when normalized with the kinematic viscosity, mean turbulent energy dissipation rate and scalar dissipation rate, are independent of the Reynolds and Péclet numbers when they are sufficiently large. In particular, there exist two scaling ranges: (i) an inertial-convective range at sufficiently large distance from the wall over which a power-law scaling emerges for all quantities mentioned above; (ii) a viscous-convective range between the viscous-diffusive and inertial-convective ranges at large Prandtl number over which the normalized scalar variance is constant. The relatively large amount of available wall turbulence data either provides reasonably good support for this hypothesis or at least exhibits a trend that is consistent with the predictions of this hypothesis. The relationship between the proposed scaling and the traditional wall scaling is discussed. Possible ultimate statistical states of wall turbulence are also proposed.
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2023 |
Djenidi L, Antonia RA, Tang SL, 'Scaling of turbulent velocity structure functions: Plausibility constraints', Journal of Fluid Mechanics, 965 (2023) [C1]
The th-order velocity structure function in homogeneous isotropic turbulence is usually represented by, where the spatial separation lies within the inertial range. The first pred... [more]
The th-order velocity structure function in homogeneous isotropic turbulence is usually represented by, where the spatial separation lies within the inertial range. The first prediction for (i.e.) was proposed by Kolmogorov (Dokl. Akad. Nauk SSSR, vol. 30, 1941) using a dimensional argument. Subsequently, starting with Kolmogorov (J. Fluid Mech., vol. 13, 1962, pp. 82-85), models for the intermittency of the turbulent energy dissipation have predicted values of that, except for, differ from. In order to assess differences between predictions of, we use the Hölder inequality to derive exact relations, denoted plausibility constraints. We first derive the constraint between the exponents, where are any three positive numbers. It is further shown that this relation leads to. It is also shown that the relation, which complies with, can be derived from constraints imposed on using the Cauchy-Schwarz inequality, a special case of the Hölder inequality. These results show that while the intermittency of, which is not ignored in the present analysis, is not incompatible with the plausible relation, the prediction is not plausible, unless.
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2023 |
Chen JG, Antonia RA, Zhou Y, 'Relationship between coherent Reynolds shear stress and large-scale vortical structures', Physics of Fluids, 35 (2023) [C1]
An equation that relates the principal derivative of the Reynolds shear stress and large-scale vorticity fluxes is developed and validated using experimental data in a cylinder ne... [more]
An equation that relates the principal derivative of the Reynolds shear stress and large-scale vorticity fluxes is developed and validated using experimental data in a cylinder near wake. When large-scale vortices prevail, the Reynolds shear stress associated with the coherent motion is a good approximation to the conventional Reynolds shear stress. The latter is essentially determined by the imbalance between the dynamic pressure arising from the streamwise non-homogeneity caused by large-scale vortical structures and the lateral coherent vorticity flux.
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2023 |
Tang SL, Antonia RA, Djenidi L, 'Dual scaling and the
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2022 |
Tang SL, Antonia RA, 'Scaling of small-scale wall turbulence', JOURNAL OF FLUID MECHANICS, 948 (2022) [C1]
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Nova |
2022 |
Tang SL, Antonia RA, Djenidi L, 'Approach towards local isotropy in statistically stationary turbulent shear flows', Journal of Fluid Mechanics, 952 (2022) [C1]
We analyse the approach towards local isotropy in statistically stationary turbulent shear flows using the transport equations for the fourth-order moments of the velocity derivat... [more]
We analyse the approach towards local isotropy in statistically stationary turbulent shear flows using the transport equations for the fourth-order moments of the velocity derivative. It is found that terms of these equations representing the large-scale contribution associated with the uniform mean velocity gradient gradually decrease as the Taylor microscale Reynolds number Re¿ increases, and finally disappear when Re¿ is sufficiently large. This gradual weakening of the large-scale effect is accompanied by a gradual approach towards local isotropy of the small-scale motion. The rate at which local isotropy is approached depends on the weakening of the large-scale forcing, which is controlled by the magnitude of the non-dimensional velocity shear parameter S* (= u21¯ (¿ U1/¿x2)/¿¯iso, where ¿iso is the isotropic mean turbulent energy dissipation rate, u21¯ is the streamwise velocity variance, and ¿ U1/¿x2 is the uniform mean velocity gradient in the transverse direction). In particular, we show that the approach towards local isotropy can be recast in the form CRe-1¿, where C is the product of S* and a ratio of transverse-to-streamwise velocity derivative variances. This is consistent with the behaviour of the normalized third-order moments of transverse velocity derivatives. With the further use of the transport equations for the eighth- and twelfth-order velocity derivative moments, it is found that the even moments of transverse velocity derivatives can significantly affect the rate at which local isotropy is approached, especially for higher orders.
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2022 |
Djenidi L, Antonia RA, Tang SL, 'Modelling the transport equation of the scalar structure function', JOURNAL OF FLUID MECHANICS, 946 (2022) [C1]
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Nova |
2021 |
Tang SL, Antonia RA, Djenidi L, 'Transport equations for the normalized nth-order moments of velocity derivatives in grid turbulence', JOURNAL OF FLUID MECHANICS, 930 (2021) [C1]
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Nova |
2021 |
Zimmerman SJ, Antonia RA, Djenidi L, Philip J, Klewicki JC, 'Approach to the 4/3 law for turbulent pipe and channel flows examined through a reformulated scale-by-scale energy budget', JOURNAL OF FLUID MECHANICS, 931 (2021) [C1]
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Nova |
2021 |
Djenidi L, Antonia RA, 'Karman-Howarth solutions of homogeneous isotropic turbulence', JOURNAL OF FLUID MECHANICS, 932 (2021) [C1]
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Nova |
2021 |
Djenidi L, Antonia RA, Tang SL, 'Mathematical constraints on the scaling exponents in the inertial range of fluid turbulence', Physics of Fluids, 33 (2021) [C1]
The dominant view in the theory of fluid turbulence assumes that, once the effect of the Reynolds number is negligible, moments of order n of the longitudinal velocity increment, ... [more]
The dominant view in the theory of fluid turbulence assumes that, once the effect of the Reynolds number is negligible, moments of order n of the longitudinal velocity increment, (d u), can be described by a simple power-law r ¿ n, where the scaling exponent ¿n depends on n and, except for ¿ 3 (= 1), needs to be determined. In this Letter, we show that applying Hölder's inequality to the power-law form (d u) n ¯ ~ (r L) ¿ n (with r / L « 1; L is an integral length scale) leads to the following mathematical constraint: ¿ 2 p = p ¿ 2. When we further apply the Cauchy-Schwarz inequality, a particular case of Hölder's inequality, to | (d u) 3 ¯ | with ¿ 3 = 1, we obtain the following constraint: ¿ 2 = 2 / 3. Finally, when Hölder's inequality is also applied to the power-law form (| d u |) n ¯ ~ (r L) ¿ n (this form is often used in the extended self-similarity analysis) while assuming ¿ 3 = 1, it leads to ¿ 2 = 2 / 3. The present results show that the scaling exponents predicted by the 1941 theory of Kolmogorov in the limit of infinitely large Reynolds number comply with Hölder's inequality. On the other hand, scaling exponents, except for ¿3, predicted by current small-scale intermittency models do not comply with Hölder's inequality, most probably because they were estimated in finite Reynolds number turbulence. The results reported in this Letter should guide the development of new theoretical and modeling approaches so that they are consistent with the constraints imposed by Hölder's inequality.
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2021 |
Kamruzzaman M, Djenidi L, Antonia RA, 'Study of the interaction of two decaying grid-generated turbulent flows', Physics of Fluids, 33 (2021) [C1]
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Nova |
2021 |
Meldi M, Djenidi L, Antonia RA, 'Sensitivity analysis of the second and third-order velocity structure functions to the Reynolds number in decaying and forced isotropic turbulence using the EDQNM model', European Journal of Mechanics, B/Fluids, 88 229-242 (2021) [C1]
Numerical calculations based on a recent version of the eddy-damped quasi-normal model (EDQNM-LMFA) are carried out for homogeneous isotropic turbulence (HIT) with the aim of inve... [more]
Numerical calculations based on a recent version of the eddy-damped quasi-normal model (EDQNM-LMFA) are carried out for homogeneous isotropic turbulence (HIT) with the aim of investigating the dependency on the Reynolds number of second and third order velocity structure functions. The quantities investigated include the energy spectrum E, the non-linear energy transfer T as well as the second (S2) and third (S3) order moments of the longitudinal velocity increment. Both free decaying HIT and (steady state) forced HIT are considered. The analysis of the structure functions for Re¿¿[50,106] indicates that, regardless of whether one considers decaying or forced HIT, the large scales affect S2 and S3 in the scaling range. In that range, forcing affects S2 and S3 differently. For forced HIT, S2/(¿¯r)2/3 exhibits a distinct ¿bump¿ near the upper end of the scaling range while no such bump is seen for S3/(¿¯r). The latter quantity remains approximately constant for values of r which extend to the scale corresponding to the forcing. For decaying HIT, there is no discernible bump in either S2/(¿¯r)2/3 or S3/(¿¯r). The slope of S3 in the scaling range approaches the theoretical value of 1, when Re¿ is sufficiently large. However, at similar Re¿, the slope of S2 has not yet reached a constant for either decaying or forced HIT.
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Nova |
2021 |
Djenidi L, Antonia RA, 'Modeling the third-order velocity structure function in the scaling range at finite Reynolds numbers', Journal of Mathematical Physics, 62 (2021) [C1]
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Nova |
2020 |
Tang SL, Antonia RA, Djenidi L, Zhou Y, 'Scaling of the turbulent energy dissipation correlation function', Journal of Fluid Mechanics, 891 (2020) [C1]
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Nova |
2020 |
Chen JG, Antonia RA, Zhou Y, Zhou TM, 'Characteristics of temperature dissipation rate in a turbulent near wake', Experimental Thermal and Fluid Science, 114 (2020) [C1]
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Nova |
2020 |
Chen JG, Zhou Y, Antonia RA, Zhou TM, 'Temperature correlations with vorticity and velocity in a turbulent cylinder wake', International Journal of Heat and Fluid Flow, 84 (2020) [C1]
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Nova |
2020 |
Djenidi L, Antonia RA, 'Assessment of large-scale forcing in isotropic turbulence using a closed Karman-Howarth equation', Physics of Fluids, 32 (2020) [C1]
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Nova |
2020 |
Browne LWB, Antonia RA, Rajagopalan S, Chambers AJ, 'Interaction region of a two-dimensional turbulent plane jet in still air. (2020)
The paper describes an experimental study to investigate the velocity and temperature fields in the interaction region of a two dimensional turbulent plane jet in still air. The e... [more]
The paper describes an experimental study to investigate the velocity and temperature fields in the interaction region of a two dimensional turbulent plane jet in still air. The experimental procedure is briefly described and the velocity and temperature variations plotted on graphs. A discussion is made, and conclusions proposed, as the link between the coherent structures observed in the mixing layer and those that were found in the self preserving far field. (A.J.)
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2020 |
Lemay J, Djenidi L, Antonia R, 'Estimation of mean turbulent kinetic energy and temperature variance dissipation rates using a spectral chart method', Physics of Fluids, 32 (2020) [C1]
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Nova |
2019 |
Abe H, Antonia RA, 'Mean temperature calculations in a turbulent channel flow for air and mercury', International Journal of Heat and Mass Transfer, 132 1152-1165 (2019) [C1]
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Nova |
2019 |
Djenidi L, Talluru KM, Antonia RA, 'A velocity defect chart method for estimating the friction velocity in turbulent boundary layers', FLUID DYNAMICS RESEARCH, 51 (2019) [C1]
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Nova |
2019 |
Chen JG, Zhou Y, Antonia RA, Zhou TM, 'The turbulent Karman vortex', JOURNAL OF FLUID MECHANICS, 871 92-112 (2019) [C1]
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Nova |
2019 |
Antonia RA, Tang SL, Djenidi L, Zhou Y, 'Finite Reynolds number effect and the 4/5 law', PHYSICAL REVIEW FLUIDS, 4 (2019) [C1]
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Nova |
2019 |
Tang S, Antonia RA, Djenidi L, Zhou Y, 'Can small-scale turbulence approach a quasi-universal state?', PHYSICAL REVIEW FLUIDS, 4 (2019) [C1]
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Nova |
2019 |
Djenidi L, Antonia RA, Tang SL, 'Scale invariance in finite Reynolds number homogeneous isotropic turbulence', Journal of Fluid Mechanics, 864 244-272 (2019) [C1]
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Nova |
2019 |
Lemay J, Djenidi L, Antonia RA, Benaissa A, 'An empirical expression for epsilon(theta) on the axis of a slightly heated turbulent round jet', JOURNAL OF FLUID MECHANICS, 867 392-413 (2019) [C1]
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Nova |
2018 |
Kamruzzaman M, Djenidi L, Antonia RA, 'Behaviour of the energy dissipation coefficient in a rough wall turbulent boundary layer', Experiments in Fluids, 59 (2018) [C1]
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Nova |
2018 |
Tang SL, Antonia RA, Djenidi L, Danaila L, Zhou Y, 'Reappraisal of the velocity derivative flatness factor in various turbulent flows', Journal of Fluid Mechanics, 847 244-265 (2018) [C1]
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Nova |
2018 |
Tang SL, Djenidi L, Antonia RA, Zhou Y, 'Secondary vortex street in the intermediate wake of a circular cylinder', Experiments in Fluids, 59 (2018) [C1]
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Nova |
2018 |
Bai HL, Zhou Y, Zhang WG, Antonia RA, 'Streamwise Vortices and Velocity Streaks in a Locally Drag-Reduced Turbulent Boundary Layer', FLOW TURBULENCE AND COMBUSTION, 100 391-416 (2018) [C1]
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Nova |
2018 |
Chen JG, Zhou Y, Antonia RA, Zhou TM, 'Characteristics of the turbulent energy dissipation rate in a cylinder wake', JOURNAL OF FLUID MECHANICS, 835 271-300 (2018) [C1]
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Nova |
2018 |
Meldi M, Djenidi L, Antonia R, 'Reynolds number effect on the velocity derivative flatness factor', JOURNAL OF FLUID MECHANICS, 856 426-443 (2018) [C1]
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Nova |
2018 |
Abe H, Antonia RA, Toh S, 'Large-scale structures in a turbulent channel flow with a minimal streamwise flow unit', JOURNAL OF FLUID MECHANICS, 850 733-768 (2018) [C1]
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Nova |
2018 |
Djenidi L, Talluru KM, Antonia RA, 'Can a turbulent boundary layer become independent of the Reynolds number?', JOURNAL OF FLUID MECHANICS, 851 (2018) [C1]
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Nova |
2017 |
Chen JG, Zhou TM, Antonia RA, Zhou Y, 'Comparison between passive scalar and velocity fields in a turbulent cylinder wake', JOURNAL OF FLUID MECHANICS, 813 667-694 (2017) [C1]
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Nova |
2017 |
Sreenivasan KR, Antonia RA, 'ON LOCAL ISOTROPY OF SMALL SCALE TEMPERATURE FLUCTUATIONS. (2017)
The measured skewness of the streamwise temperature derivative in both laboratory and atmospheric turbulent flows has been found to be non-zero (and of either sign) and essentiall... [more]
The measured skewness of the streamwise temperature derivative in both laboratory and atmospheric turbulent flows has been found to be non-zero (and of either sign) and essentially independent of Reynolds number, for a sufficiently large value of the Reynolds number. The apparent contradiction of this result with the hypothesis of local isotropy is examined here in the context of accumulating evidence for the presence of a highly organized large scale motion in turbulent shear flows. In the temperature trace, the signature of the large scale motion appears as a 'ramp-like' structure on which small scale fluctuations are superimposed. The measured non-zero skewness of the temperature derivative does not contradict local isotropy, as it appears to be almost entirely due to the non-isotropic large scale structure.
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2017 |
Djenidi L, Antonia RA, Danaila L, 'Self-preservation relation to the Kolmogorov similarity hypotheses', PHYSICAL REVIEW FLUIDS, 2 (2017) [C1]
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Nova |
2017 |
Abe H, Antonia RA, 'Relationship between the heat transfer law and the scalar dissipation function in a turbulent channel flow', JOURNAL OF FLUID MECHANICS, 830 300-325 (2017) [C1]
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Nova |
2017 |
Djenidi L, Lefeuvre N, Kamruzzaman M, Antonia RA, 'On the normalized dissipation parameter C-epsilon in decaying turbulence', JOURNAL OF FLUID MECHANICS, 817 61-79 (2017) [C1]
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Nova |
2017 |
Tang SL, Antonia RA, Djenidi L, Danaila L, Zhou Y, 'Finite Reynolds number effect on the scaling range behaviour of turbulent longitudinal velocity structure functions', JOURNAL OF FLUID MECHANICS, 820 341-369 (2017) [C1]
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Nova |
2017 |
Antonia RA, Djenidi L, Danaila L, Tang SL, 'Small scale turbulence and the finite Reynolds number effect', PHYSICS OF FLUIDS, 29 (2017) [C1]
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Nova |
2017 |
Djenidi L, Danaila L, Antonia RA, Tang S, 'A note on the velocity derivative flatness factor in decaying HIT', PHYSICS OF FLUIDS, 29 (2017) [C1]
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Nova |
2017 |
Djenidi L, Antonia RA, Talluru MK, Abe H, 'Skewness and flatness factors of the longitudinal velocity derivative in wall-bounded flows', PHYSICAL REVIEW FLUIDS, 2 (2017) [C1]
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Nova |
2016 |
Djenidi L, Antonia RA, Lefeuvre N, Lemay J, 'Complete self-preservation on the axis of a turbulent round jet', Journal of Fluid Mechanics, 790 57-70 (2016) [C1]
Self-preservation (SP) solutions on the axis of a turbulent round jet are derived for the transport equation of the second-order structure function of the turbulent kinetic energy... [more]
Self-preservation (SP) solutions on the axis of a turbulent round jet are derived for the transport equation of the second-order structure function of the turbulent kinetic energy , which may be interpreted as a scale-by-scale (s.b.s.) energy budget. The analysis shows that the mean turbulent energy dissipation rate, , evolves like ( is the streamwise direction). It is important to stress that this derivation does not use the constancy of the non-dimensional dissipation rate parameter ( and are the integral length scale and root mean square of the longitudinal velocity fluctuation respectively). We show, in fact, that the constancy of is simply a consequence of complete SP (i.e. SP at all scales of motion). The significance of the analysis relates to the fact that the SP requirements for the mean velocity and mean turbulent kinetic energy (i.e. and respectively) are derived without invoking the transport equations for and . Experimental hot-wire data along the axis of a turbulent round jet show that, after a transient downstream distance which increases with Reynolds number, the turbulence statistics comply with complete SP. For example, the measured agrees well with the SP prediction, i.e. , while the Taylor microscale Reynolds number remains constant. The analytical expression for the prefactor for (where is a virtual origin), first developed by Thiesset et al. (J. Fluid Mech., vol. 748, 2014, R2) and rederived here solely from the SP analysis of the s.b.s. energy budget, is validated and provides a relatively simple and accurate method for estimating along the axis of a turbulent round jet.
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Nova |
2016 |
Tang SL, Antonia RA, Djenidi L, Zhou Y, 'Complete self-preservation along the axis of a circular cylinder far wake', Journal of Fluid Mechanics, 786 253-274 (2016) [C1]
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Nova |
2016 |
Tang SL, Antonia RA, Djenidi L, Danaila L, Zhou Y, 'Boundedness of the mixed velocity-temperature derivative skewness in homogeneous isotropic turbulence', Physics of Fluids, 28 (2016) [C1]
The transport equation for the mean scalar dissipation rate ¿¿ is derived by applyingthe limit at small separations to the generalized form of Yaglom's equation in twotypes o... [more]
The transport equation for the mean scalar dissipation rate ¿¿ is derived by applyingthe limit at small separations to the generalized form of Yaglom's equation in twotypes of flows, those dominated mainly by a decay of energy in the streamwisedirection and those which are forced, through a continuous injection of energy atlarge scales. In grid turbulence, the imbalance between the production of ¿¿ dueto stretching of the temperature field and the destruction of ¿¿ by the thermaldiffusivity is governed by the streamwise advection of ¿¿ by the mean velocity.This imbalance is intrinsically different from that in stationary forced periodic boxturbulence (or SFPBT), which is virtually negligible. In essence, the different typesof imbalance represent different constraints imposed by the large-scale motion on therelation between the so-called mixed velocity-temperature derivative skewness STand the scalar enstrophy destruction coefficient G¿ in different flows, thus resultingin non-universal approaches of ST towards a constant value as Re¿ increases. Thedata for ST collected in grid turbulence and in SFPBT indicate that the magnitudeof ST is bounded, this limit being close to 0.5.
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Nova |
2016 |
Abe H, Antonia RA, 'Relationship between the energy dissipation function and the skin friction law in a turbulent channel flow', JOURNAL OF FLUID MECHANICS, 798 140-164 (2016) [C1]
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Nova |
2016 |
Chen JG, Zhou Y, Zhou TM, Antonia RA, 'Three-dimensional vorticity, momentum and heat transport in a turbulent cylinder wake', Journal of Fluid Mechanics, 809 135-167 (2016) [C1]
The transport of momentum and heat in the turbulent intermediate wake of a circular cylinder is inherently three-dimensional (3-D). This work aims to gain new insight into the 3-D... [more]
The transport of momentum and heat in the turbulent intermediate wake of a circular cylinder is inherently three-dimensional (3-D). This work aims to gain new insight into the 3-D vorticity structure, momentum and heat transport in this flow. All three components of the velocity and vorticity vectors, along with the fluctuating temperature, are measured simultaneously, at nominally the same point in the flow, with a probe consisting of four X-wires and four cold wires. Measurements are made in the ( , ) or mean shear plane at , 20 and 40 at a Reynolds number of based on the cylinder diameter and the free-stream velocity. A phase-averaging technique is developed to separate the large-scale coherent structures from the remainder of the flow. It is found that the effects of vorticity on heat transport at and are distinctly different. At , both spanwise and streamwise vorticity components account significantly for the heat flux. At and 40, the spanwise vortex rollers play a major role in inducing the coherent components of the heat flux vector, while the ribs are responsible for the small-scale heat diffusion out of the spanwise vortex rollers. The present data indicate that, if the spanwise-velocity-related terms are ignored, the estimated values of the production can have errors of approximately 22 % and 13 % respectively for the turbulent energy and temperature variance at , and the errors are expected to further increase downstream. A conceptual model summarizing the 3-D features of the heat and momentum transports at is proposed. Compared with the previous two-dimensional model of Matsumura & Antonia (J. Fluid Mech., vol. 250, 1993, pp. 651-668) or MA, the new model provides a more detailed description of the role the rib-like structures undertake in transporting heat and momentum, and also underlines the importance of the upstream half of the spanwise vortex rollers, instead of only one quadrant of these rollers, as in the MA model, in diffusing heat out of the vortex.
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Nova |
2016 |
Tang SL, Antonia RA, Danaila L, Djenidi L, Zhou T, Zhou Y, 'Towards local isotropy of higher-order statistics in the intermediate wake', EXPERIMENTS IN FLUIDS, 57 (2016) [C1]
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Nova |
2016 |
Talluru KM, Djenidi L, Kamruzzaman M, Antonia RA, 'Self-preservation in a zero pressure gradient rough-wall turbulent boundary layer', JOURNAL OF FLUID MECHANICS, 788 57-69 (2016) [C1]
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Nova |
2015 |
Tang SL, Djenidi L, Antonia RA, Zhou Y, 'Comparison between velocity- and vorticity-based POD methods in a turbulent wake', Experiments in Fluids, 56 (2015) [C1]
In this paper, the velocity-based POD and the vorticity-based POD have been systematically compared in three characteristic regions of the flow downstream of a two-dimensional cir... [more]
In this paper, the velocity-based POD and the vorticity-based POD have been systematically compared in three characteristic regions of the flow downstream of a two-dimensional circular cylinder, namely the near, intermediate and far wakes. The two-point space correlation function is used to determine which of the two methods is better suited for extracting the large-scale flow structures based on the repartition of energy among the different POD modes. It is found that the POD, based on the lateral velocity fluctuation v, leads to the most optimum extraction in all three flow regions, while the vorticity-based POD is only effective in the near and intermediate wakes. Based on two-point space correlation functions, a scenario is proposed for the application of POD to the present two-dimensional wake.
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Nova |
2015 |
Kamruzzaman M, Djenidi L, Antonia RA, Talluru KM, 'Scale-by-scale energy budget in a turbulent boundary layer over a rough wall', International Journal of Heat and Fluid Flow, (2015) [C1]
Hot-wire velocity measurements are carried out in a turbulent boundary layer over a rough wall consisting of transverse circular rods, with a ratio of 8 between the spacing (w) of... [more]
Hot-wire velocity measurements are carried out in a turbulent boundary layer over a rough wall consisting of transverse circular rods, with a ratio of 8 between the spacing (w) of two consecutive rods and the rod height (k). The pressure distribution around the roughness element is used to accurately measure the mean friction velocity (Ut) and the error in the origin. It is found that Ut remained practically constant in the streamwise direction suggesting that the boundary layer over this surface is evolving in a self-similar manner. This is further corroborated by the similarity observed at all scales of motion, in the region 0.2=y/d=0.6, as reflected in the constancy of Reynolds number (R¿) based on Taylor's microscale and the collapse of Kolmogorov normalized velocity spectra at all wavenumbers.A scale-by-scale budget for the second-order structure function <(du)2> (du=u(x+r)-u(x), where u is the fluctuating streamwise velocity component and r is the longitudinal separation) is carried out to investigate the energy distribution amongst different scales in the boundary layer. It is found that while the small scales are controlled by the viscosity, intermediate scales over which the transfer of energy (or <(du)3>) is important are affected by mechanisms induced by the large-scale inhomogeneities in the flow, such as production, advection and turbulent diffusion. For example, there are non-negligible contributions from the large-scale inhomogeneity to the budget at scales of the order of ¿, the Taylor microscale, in the region of the boundary layer extending from y/d=0.2 to 0.6 (d is the boundary layer thickness).
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Nova |
2015 |
Tang SL, Antonia RA, Djenidi L, Zhou Y, 'Transport equation for the isotropic turbulent energy dissipation rate in the far-wake of a circular cylinder', Journal of Fluid Mechanics, 784 109-129 (2015) [C1]
The transport equation for the isotropic turbulent energy dissipation rate along the centreline in the far-wake of a circular cylinder is derived by applying the limit at small se... [more]
The transport equation for the isotropic turbulent energy dissipation rate along the centreline in the far-wake of a circular cylinder is derived by applying the limit at small separations to the two-point energy budget equation. It is found that the imbalance between the production and the destruction of eiso, respectively due to vortex stretching and viscosity, is governed by both the streamwise advection and the lateral turbulent diffusion (the former contributes more to the budget than the latter). This imbalance differs intrinsically from that in other flows, e.g. grid turbulence and the flow along the centreline of a fully developed channel, where either the streamwise advection or the lateral turbulent diffusion of eiso governs the imbalance. More importantly, the different types of imbalance represent different constraints on the relation between the skewness of the longitudinal velocity derivative and the destruction coefficient of enstrophy G. This results in a non-universal approach of towards a constant value as the Taylor microscale Reynolds number R¿ increases. For the present flow, the magnitude of S decreases initially before increasing (R¿ > 40) towards this constant value. The constancy of S at large R¿ violates the modified similarity hypothesis introduced by Kolmogorov (J. Fluid Mech., vol. 13, 1962, pp. 82-85) but is consistent with the original similarity hypotheses (Kolmogorov, Dokl. Akad. Nauk SSSR, vol. 30, 1941b, pp. 299-303 (see also 1991 Proc. R. Soc. Lond. A, vol. 434, pp. 9-13)) , and, more importantly, with the almost completely self-preserving nature of the plane far-wake.
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Nova |
2015 |
Leonardi S, Orlandi P, Djenidi L, Antonia RA, 'Heat transfer in a turbulent channel flow with square bars or circular rods on one wall', Journal of Fluid Mechanics, 776 512-530 (2015) [C1]
Direct numerical simulations (DNS) are carried out to study the passive heat transport in a turbulent channel flow with either square bars or circular rods on one wall. Several va... [more]
Direct numerical simulations (DNS) are carried out to study the passive heat transport in a turbulent channel flow with either square bars or circular rods on one wall. Several values of the pitch to height ratio and two Reynolds numbers are considered. The roughness increases the heat transfer by inducing ejections at the leading edge of the roughness elements. The amounts of heat transfer and mixing depend on the separation between the roughness elements, an increase in heat transfer accompanying an increase in drag. The ratio of non-dimensional heat flux to the non-dimensional wall shear stress is higher for circular rods than square bars irrespectively of the pitch to height ratio. The turbulent heat flux varies within the cavities and is larger near the roughness elements. Both momentum and thermal eddy diffusivities increase relative to the smooth wall. For square cavities the turbulent Prandtl number is smaller than for a smooth channel near the wall. As increases, the turbulent Prandtl number increases up to a maximum of 2.5 at the crests plane of the square bars . With increasing distance from the wall, the differences with respect to the smooth wall vanish and at three roughness heights above the crests plane, the turbulent Prandtl number is essentially the same for smooth and rough walls.
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2015 |
Tang SL, Antonia RA, Djenidi L, Abe H, Zhou T, Danaila L, Zhou Y, 'Transport equation for the mean turbulent energy dissipation rate on the centreline of a fully developed channel flow', Journal of Fluid Mechanics, 777 151-177 (2015) [C1]
The transport equation for the mean turbulent energy dissipation rate along the centreline of a fully developed channel flow is derived by applying the limit at small separations ... [more]
The transport equation for the mean turbulent energy dissipation rate along the centreline of a fully developed channel flow is derived by applying the limit at small separations to the two-point budget equation. Since the ratio of the isotropic energy dissipation rate to the mean turbulent energy dissipation rate is sufficiently close to 1 on the centreline, our main focus is on the isotropic form of the transport equation. It is found that the imbalance between the production of due to vortex stretching and the destruction of caused by the action of viscosity is governed by the diffusion of by the wall-normal velocity fluctuation. This imbalance is intrinsically different from the advection-driven imbalance in decaying-type flows, such as grid turbulence, jets and wakes. In effect, the different types of imbalance represent different constraints on the relation between the skewness of the longitudinal velocity derivative and the destruction coefficient of enstrophy in different flows, thus resulting in non-universal approaches of towards a constant value as the Taylor microscale Reynolds number, , increases. For example, the approach is slower for the measured values of along either the channel or pipe centreline than along the axis in the self-preserving region of a round jet. The data for collected in different flows strongly suggest that, in each flow, the magnitude of is bounded, the value being slightly larger than 0.5.
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2015 |
Djenidi L, Antonia RA, 'A general self-preservation analysis for decaying homogeneous isotropic turbulence', Journal of Fluid Mechanics, 773 345-365 (2015) [C1]
A general framework of self-preservation (SP) is established, based on the transport equation of the second-order longitudinal velocity structure function in decaying homogeneous ... [more]
A general framework of self-preservation (SP) is established, based on the transport equation of the second-order longitudinal velocity structure function in decaying homogeneous isotropic turbulence (HIT). The analysis introduces the skewness of the longitudinal velocity increment, S(r, t) (r and t are space increment and time), as an SP controlling parameter. The present SP framework allows a critical appraisal of the specific assumptions that have been made in previous SP analyses. It is shown that SP is achieved when S(r, t) varies in a self-similar manner, i.e. S=c(t)f(r/l) where l is a scaling length, and c(t) and f(r/l) are dimensionless functions of time and (r/l), respectively. When c(t) is constant, l can be identified with the Kolmogorov length scale ¿, even when the Reynolds number is relatively small. On the other hand, the Taylor microscale ¿ is a relevant SP length scale only when certain conditions are met. The decay law for the turbulent kinetic energy (k) ensuing from the present SP is a generalization of the existing laws and can be expressed as k ~ (t-t0)n+B, where B is a constant representing the energy of the motions whose scales are excluded from the SP range of scales. When B = 0, SP is achieved at all scales of motion and ¿ becomes a relevant scaling length together with ¿. The analysis underlines the relation between the initial conditions and the power-law exponent n and also provides a link between them. In particular, an expression relating n to the initial values of the scaling length and velocity is developed. Finally, the present SP analysis is consistent with both experimental grid turbulence data and the eddy-damped quasi-normal Markovian numerical simulation of decaying HIT by Meldi & Sagaut (J. Turbul., vol. 14, 2013, pp. 24-53).
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2015 |
Djenidi L, Kamruzzaman M, Antonia RA, 'Power-law exponent in the transition period of decay in grid turbulence', JOURNAL OF FLUID MECHANICS, 779 (2015) [C1]
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2015 |
Kamruzzaman M, Djenidi L, Antonia RA, Talluru KM, 'Drag of a turbulent boundary layer with transverse 2D circular rods on the wall', EXPERIMENTS IN FLUIDS, 56 (2015) [C1]
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Nova |
2015 |
Antonia RA, Tang SL, Djenidi L, Danaila L, 'Boundedness of the velocity derivative skewness in various turbulent flows', Journal of Fluid Mechanics, 781 727-744 (2015) [C1]
The variation of S, the velocity derivative skewness, with the Taylor microscale Reynolds number Re¿ is examined for different turbulent flows by considering the locally isotropic... [more]
The variation of S, the velocity derivative skewness, with the Taylor microscale Reynolds number Re¿ is examined for different turbulent flows by considering the locally isotropic form of the transport equation for the mean energy dissipation rate e¯iso. In each flow, the equation can be expressed in the form S C 2G=Re¿ D C=Re¿, where G is a non-dimensional rate of destruction of e¯iso and C is a flow-dependent constant. Since 2G=Re¿ is found to be very nearly constant for Re¿ = 70, S should approach a universal constant when Re¿ is sufficiently large, but the way this constant is approached is flow dependent. For example, the approach is slow in grid turbulence and rapid along the axis of a round jet. For all the flows considered, the approach is reasonably well supported by experimental and numerical data. The constancy of S at large Re¿ has obvious ramifications for small-scale turbulence research since it violates the modified similarity hypothesis introduced by Kolmogorov (J. Fluid Mech., vol. 13, 1962, pp. 82-85) but is consistent with the original similarity hypothesis (Kolmogorov, Dokl. Akad. Nauk SSSR, vol. 30, 1941, pp. 299-303).
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2014 |
Thiesset F, Antonia RA, Djenidi L, 'Consequences of self-preservation on the axis of a turbulent round jet', JOURNAL OF FLUID MECHANICS, 748 (2014) [C1]
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Nova |
2014 |
Thiesset F, Danaila L, Antonia RA, 'Dynamical interactions between the coherent motion and small scales in a cylinder wake', JOURNAL OF FLUID MECHANICS, 749 201-226 (2014) [C1]
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Nova |
2014 |
Djenidi L, Antonia RA, 'Transport equation for the mean turbulent energy dissipation rate in low-R-lambda grid turbulence', JOURNAL OF FLUID MECHANICS, 747 288-315 (2014) [C1]
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Nova |
2014 |
Bai HL, Zhou Y, Zhang WG, Xu SJ, Wang Y, Antonia RA, 'Active control of a turbulent boundary layer based on local surface perturbation', JOURNAL OF FLUID MECHANICS, 750 316-354 (2014) [C1]
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2014 |
Lee SK, Djenidi L, Antonia RA, 'Empirical correlations for slightly heated decaying passive-grid turbulence', Heat Transfer Engineering, 35 1482-1490 (2014) [C1]
For homogeneous isotropic turbulence approximated by grid turbulence, velocity and temperature fluctuations decay under the effects of viscosity and thermal diffusivity of the flu... [more]
For homogeneous isotropic turbulence approximated by grid turbulence, velocity and temperature fluctuations decay under the effects of viscosity and thermal diffusivity of the fluid. In the self-similar region of grid flow, there is no mean shear and no turbulence production, and the decay rate is well represented by a power law; this is supported by the present measurements in three different grid flows and by previously published data for passive-grid turbulence obtained over different ranges of streamwise distance and/or Reynolds number. The grid flow is slightly heated so that temperature acts as a passive scalar. From dimensional analysis and empirical power-law correlations, relations for basic flow parameters, such as the Kolmogorov, Taylor, and Corrsin microscales, and the Reynolds and Péclet numbers, are established as functions of the normalized streamwise distance downstream of the grid. With these relations, it is possible to determine the flow parameters for a specific passive-grid geometry or, more generally, a specific set of initial conditions. © 2014 Copyright Taylor & Francis Group, LLC.
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2014 |
Djenidi L, Antonia RA, Amielh M, Anselmet F, 'Use of PIV to highlight possible errors in hot-wire Reynolds stress data over a 2D rough wall', EXPERIMENTS IN FLUIDS, 55 (2014) [C1]
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2014 |
Lefeuvre N, Thiesset F, Djenidi L, Antonia RA, 'Statistics of the turbulent kinetic energy dissipation rate and its surrogates in a square cylinder wake flow', Physics of Fluids, 26 (2014) [C1]
A numerical simulation based on the lattice Boltzmann method is carried out in the wake of a square cylinder with the view to investigating possible surrogates for the instantaneo... [more]
A numerical simulation based on the lattice Boltzmann method is carried out in the wake of a square cylinder with the view to investigating possible surrogates for the instantaneous turbulent kinetic energy dissipation rate, Ie{cyrillic, ukrainian}, as well as its mean value, \documentclass[12pt]{minimal}\begin{document}$\overline{\epsilon }$\end{document}Ie{cyrillic, ukrainian}. Various surrogate approximations of Ie{cyrillic, ukrainian}, based on local isotropy (Ie{cyrillic, ukrainian}iso), local axisymmetry along the streamwise direction x (Ie{cyrillic, ukrainian}a, x) and the transverse direction y (Ie{cyrillic, ukrainian}a, y), local homogeneity (Ie{cyrillic,ukrainian}hom), and homogeneity in the transverse plane, (Ie{cyrillic,ukrainian}4x), are assessed. All the approximations are in agreement with \documentclass[12pt]{minimal}\begin{document}$\overline{\epsilon }$\end{document}Ie{cyrillic,ukrainian}when the distance downstream of the obstacle is larger than about 40 diameters. Closer to the obstacle, the agreement remains reasonable only for \documentclass[12pt]{minimal}\begin{document}$\overline{\epsilon }_{a,x}$\end{document}Ie{cyrillic, ukrainian}a,x, \documentclass[12pt]{minimal}\begin{document}$\overline{\epsilon }{hom}$\end{document}?hom and \documentclass[12pt]{minimal}\begin{document}$\overline{\epsilon }{4x}$\end{document}Ie{cyrillic, ukrainian}4x. The probability density functions (PDF) and joint PDFs of Ie{cyrillic, ukrainian} and its surrogates show that Ie{cyrillic, ukrainian}4x correlates best withIe{cyrillic, ukrainian}while ?iso and Ie{cyrillic, ukrainian}hom present the smallest correlation. The results indicate that Ie{cyrillic, ukrainian}4x is a very good surrogate for Ie{cyrillic, ukrainian}and can be used for correctly determining the behaviour of Ie{cyrillic, ukrainian}.
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2014 |
Antonia RA, Djenidi L, Danaila L, 'Collapse of the turbulent dissipative range on Kolmogorov scales', PHYSICS OF FLUIDS, 26 (2014) [C1]
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Nova |
2014 |
Thiesset F, Schaeffer V, Djenidi L, Antonia RA, 'On self-preservation and log-similarity in a slightly heated axisymmetric mixing layer', PHYSICS OF FLUIDS, 26 (2014) [C1]
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Nova |
2014 |
Djenidi L, Tardu SF, Antonia RA, Danaila L, 'Breakdown of Kolmogorov's first similarity hypothesis in grid turbulence', JOURNAL OF TURBULENCE, 15 596-610 (2014) [C1]
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Nova |
2013 |
Antonia RA, Lee SK, Djenidi L, Lavoie P, Danaila L, 'Invariants for slightly heated decaying grid turbulence', JOURNAL OF FLUID MECHANICS, 727 379-406 (2013) [C1]
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Nova |
2013 |
Thiesset F, Danaila L, Antonia RA, 'Dynamical effect of the total strain induced by the coherent motion on local isotropy in a wake', Journal of Fluid Mechanics, 720 393-423 (2013) [C1]
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Nova |
2013 |
Rajagopalan S, Antonia RA, Djenidi L, 'Effect of mesh grids on the turbulent mixing layer of an axisymmetric jet', Heat Transfer Engineering, 34 1216-1225 (2013) [C1]
This article focuses on the effect that two different mesh grids have on the structure of the mixing layer of an axisymmetric jet. Detailed measurements of mean velocity and turbu... [more]
This article focuses on the effect that two different mesh grids have on the structure of the mixing layer of an axisymmetric jet. Detailed measurements of mean velocity and turbulent velocity fluctuations are made with an X hot-wire probe in the range 0.5 = x/d = 10, where x is the longitudinal distance from the nozzle exit plane and d is the nozzle diameter. The grids are introduced at two locations-one location just downstream of the nozzle exit plane and the other location upstream of the nozzle exit plane in order to perturb the nozzle exit boundary layer. One mesh completely covers the nozzle (full mesh or FM) and the other mesh covers the central, high-speed zone (disk mesh or DM). With reference to the undisturbed jet, FM yields a significant reduction in the turbulence intensity and width of the shear layer, whereas DM enhances the turbulence intensity and increases the width of the shear layer. Both grids suppress the formation of the Kelvin-Helmholtz instability in the mixing layer. Results are presented, mainly at x/d = 5 and 6 in both the spectral domain and physical space. In the latter context, second-and third-order structure functions associated with u (the longitudinal velocity fluctuation) and v (the lateral or radial velocity fluctuation) are presented only for the flow perturbed by placing the mesh outside the nozzle. All mesh geometries have a more significant effect on the second-order structure function of u than on that of v. The third-order energy transfer term is affected in such a way that, relative to the undisturbed jet, its peak location is shifted to a smaller scale when FM is used and to a larger scale with DM. This is consistent with our observations that FM reduces the turbulence in the shear layer while DM enhances it. It is suggested that the large-scale vortices that are formed at the edge of the grids play a significant role in the transfer of energy. © 2013 Taylor & Francis Group, LLC.
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2013 |
Thiesset F, Antonia RA, Danaila L, 'Scale-by-scale turbulent energy budget in the intermediate wake of two-dimensional generators', PHYSICS OF FLUIDS, 25 (2013) [C1]
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Nova |
2013 |
Thiesset F, Antonia RA, Danaila L, 'Restricted scaling range models for turbulent velocity and scalar energy transfers in decaying turbulence', JOURNAL OF TURBULENCE, 14 25-41 (2013) [C1]
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Nova |
2013 |
Djenidi L, Tardu SF, Antonia RA, 'Relationship between temporal and spatial averages in grid turbulence', Journal of Fluid Mechanics, 730 593-606 (2013) [C1]
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Nova |
2013 |
Thiesset F, Antonia RA, Danaila L, Djenidi L, 'Karman-Howarth closure equation on the basis of a universal eddy viscosity', PHYSICAL REVIEW E, 88 (2013) [C1]
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Nova |
2012 |
Danaila L, Antonia RA, Burattini P, 'Comparison between kinetic energy and passive scalar energy transfer in locally homogeneous isotropic turbulence', Physica D: Nonlinear Phenomena, 241 224-231 (2012) [C1]
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Nova |
2012 |
Djenidi L, Antonia RA, 'A spectral chart method for estimating the mean turbulent kinetic energy dissipation rate', Experiments in Fluids, 53 1005-1013 (2012) [C1]
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Nova |
2012 |
Lee S-K, Benaissa A, Djenidi L, Lavoie P, Antonia RA, 'Decay of passive-scalar fluctuations in slightly stretched grid turbulence', Experiments in Fluids, 53 909-923 (2012) [C1]
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Nova |
2012 |
Lee SK, Benaissa A, Djenidi L, Lavoie P, Antonia RA, 'Scaling range of velocity and passive scalar spectra in grid turbulence (vol 24, 075101, 2012)', PHYSICS OF FLUIDS, 24 (2012) [C3]
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2012 |
Lee S-K, Benaissa A, Djenidi L, Lavoie P, Antonia RA, 'Scaling range of velocity and passive scalar spectra in grid turbulence', Physics of Fluids, 24 (2012) [C1]
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Nova |
2011 |
Mi J, Xu M, Antonia RA, Wang JJ, 'Thermal characteristics of the wake shear layers from a slightly heated circular cylinder', Experiments in Fluids, 50 429-441 (2011) [C1]
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Nova |
2011 |
Abe H, Antonia RA, 'Scaling of normalized mean energy and scalar dissipation rates in a turbulent channel flow', Physics of Fluids, 23 (2011) [C1]
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Nova |
2010 |
Djenidi L, Antonia R, Amielh M, Anselmet F, 'POD analysis of the near-wall region of a rough wall turbulent boundary layer', IUTAM Bookseries, 22 49-54 (2010)
A proper orthogonal decomposition (POD) analysis is carried out with particle image velocity (PIV) measurements of a turbulent boundary layer over a rough wall made of transverse ... [more]
A proper orthogonal decomposition (POD) analysis is carried out with particle image velocity (PIV) measurements of a turbulent boundary layer over a rough wall made of transverse square bars. Two bar spacings were investigated (w/k = 3 and 7, w is the bar spacing and k the bar diameter). This ratio affects the energy distribution amongst the POD modes throughout the boundary layer, the higher modes, i.e. the relatively small-scale and less energetic motions, being the most perturbed. The first few near-wall POD modes were also affected by the spacing. © Springer Science+Business Media B.V. 2010.
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2010 |
Mi J-C, Antonia RA, 'Key Factors in Determining the Magnitude of Vorticity in Turbulent Plane Wakes', Chinese Physics Letters, 27 1-4 (2010) [C1]
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Nova |
2010 |
Agrawal A, Djenidi L, Antonia RA, 'Near-field measurements and development of a new boundary layer over a flat plate with localized suction', Experiments in Fluids, 48 747-762 (2010) [C1]
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Nova |
2010 |
Antonia RA, Lavoie P, Djenidi L, Benaissa A, 'Effect of a small axisymmetric contraction on grid turbulence', Experiments in Fluids, 49 3-10 (2010) [C1]
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Nova |
2010 |
Mi J, Antonia RA, 'Approach to local axisymmetry in a turbulent cylinder wake', Experiments in Fluids, 48 933-947 (2010) [C1]
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Nova |
2010 |
Burattini P, Falchi M, Romano GP, Antonia RA, 'PIV and hot wire measurements in the far field of turbulent round jets', Measurement Science & Technology, 21 1-15 (2010) [C1]
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Nova |
2009 |
Abe H, Antonia RA, 'Near-wall similarity between velocity and scalar fluctuations in a turbulent channel flow', Physics of Fluids, 21 025109 (2009) [C1]
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Nova |
2009 |
Abe H, Antonia RA, Kawamura H, 'Correlation between small-scale velocity and scalar fluctuations in a turbulent channel flow', Journal of Fluid Mechanics, 627 1-32 (2009) [C1]
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Nova |
2009 |
Antonia RA, Abe H, Kawamura H, 'Analogy between velocity and scalar fields in a turbulent channel flow', Journal of Fluid Mechanics, 62 241-268 (2009) [C1]
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Nova |
2009 |
Djenidi L, Antonia RA, 'Momentum and heat transport in a three-dimensional transitional wake of a heated square cylinder', Journal of Fluid Mechanics, 640 109-129 (2009) [C1]
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Nova |
2009 |
Djenidi L, Agrawal A, Antonia RA, 'Anisotropy measurements in the boundary layer over a flat plate with suction', Experimental Thermal and Fluid Science, 33 1106-1111 (2009) [C1]
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Nova |
2009 |
Danaila L, Antonia RA, 'Spectrum of a passive scalar in moderate Reynolds number homogenous isotropic turbulence', Physics of Fluids, 21 111702 (2009) [C1]
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Nova |
2008 |
Burattini P, Leonardi S, Orlandi P, Antonia RA, 'Comparison between experiments and direct numerical simulations in a channel flow with roughness on one wall', Journal of Fluid Mechanics, 600 403-426 (2008) [C1]
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Nova |
2008 |
Oyewola O, Djenidi L, Antonia RA, 'Response of mean turbulent energy dissipation rate and spectra to concentrated wall suction', Experiments in Fluids, 44 159-165 (2008) [C1]
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Nova |
2008 |
Djenidi L, Antonia RA, Amielh M, Anselmet F, 'A turbulent boundary layer over a two-dimensional rough wall', Experiments in Fluids, 44 37-47 (2008) [C1]
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Nova |
2008 |
Burattini P, Lavoie P, Antonia RA, 'Velocity derivative skewness in isotropic turbulence and its measurement with hot wires', Experiments in Fluids, 45 523-535 (2008) [C1]
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Nova |
2007 |
Lavoie P, Avallone G, De Gregorio F, Romano GP, Antonia RA, 'Spatial resolution of PIV for the measurement of turbulence', Experiments in Fluids, 43 39-51 (2007) [C1]
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2007 |
Oyewola O, Djenidi L, Antonia RA, 'Influence of localised double suction on a turbulent boundary layer', Journal of Fluids and Structures, 23 787-798 (2007) [C1]
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2007 |
Oyewola MO, Djenidi L, Antonia RA, 'Examination of anisotropy of the small-scale motion in a perturbed low Reynolds number turbulent boundary layer', Experimental Thermal and Fluid Science, 32 309-315 (2007) [C1]
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2007 |
Leonardi S, Orlandi P, Antonia RA, 'Properties of d- and k-type roughness in a turbulent channel flow', Physics of Fluids, 19 125101 (2007) [C1]
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Nova |
2007 |
Burattini P, Lavoie P, Antonia RA, 'Velocity derivative skewness in isotropic turbulence and its measurement with hot wires', Proceedings of the 16th Australasian Fluid Mechanics Conference, 16AFMC, 287-290 (2007)
We investigate the effect of the hot wire resolution on measurements of the velocity derivative skewness in homogeneous isotropic turbulence. A single wire configuration (with dif... [more]
We investigate the effect of the hot wire resolution on measurements of the velocity derivative skewness in homogeneous isotropic turbulence. A single wire configuration (with different lengths and temporal sampling resolutions) is considered. Estimates of the attenuation, based on numerical data in box turbulence, are applied to experimental data taken in grid turbulence. It is found that the sampling resolution has a sizeable attenuation effect, while the length of the wire has a relatively minor impact. The corrected experimental values support the conclusion that the skewness is constantwith the Reynolds number, in agreement with Kolmogorov's 41 theory.
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2007 |
Benaissa A, Djenidi L, Antonia RA, Parker R, 'Effect of initial conditions on the scalar decay in grid turbulence at low R
Decaying grid turbulence is considered at low Reynolds number (R ¿~ 50) for different initial conditions. Three different grid geometries are used. Heat is injected via a mandolin... [more]
Decaying grid turbulence is considered at low Reynolds number (R ¿~ 50) for different initial conditions. Three different grid geometries are used. Heat is injected via a mandoline at a distance of 1.5 M from the grid. The amount of heating is such that temperature may be treated as a passive scalar. A small contraction (1.36:1) is added at a distance of 11M downstream of the grid. The power-law exponents for the scalar variance are compared with those for the turbulent kinetic energy. These exponents depend on the grid geometry. For the isotropic dissipation rate (Chi;) iso, the power-law exponent agrees with that inferred from the temperature variance transport equation. Restricting the range of validity of the decay law affects the magnitudes of the origin and decay exponent. Secondorder temperature structure functions collapse when the normalization is based on the local temperature variance and the Corrsin microscale but the asymptotic form of this collapse depends on the initial conditions.
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2007 |
Lavoie PLD, Djenidi L, Antonia RA, 'Effects of initial conditions in decaying turbulence generated by passive grids', Journal of Fluid Mechanics, 585 395-420 (2007) [C1]
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Nova |
2007 |
Rajagopalan SR, Antonia RA, 'Turbulence and drag control in jet and wake flows', Sadhana - Academy Proceedings in Engineering Sciences, 32 133-144 (2007) [C1]
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2007 |
Xu G, Antonia RA, Rajagopalan SR, 'Scaling of mixed longitudinal-transverse velocity structure functions', Europhysics Letters, 79 44001 (2007) [C1]
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Nova |
2006 |
Antonia RA, Burattini P, 'Approach to the 4/5 law in homogeneous isotropic turbulence', Journal of Fluid Mechanics, 550 175-184 (2006) [C1]
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Nova |
2006 |
Orlandi P, Leonardi S, Antonia RA, 'Turbulent channel flow with either transverse or longitudinal roughness elements on one wall', Journal of Fluid Mechanics, 561 279-305 (2006) [C1]
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Nova |
2006 |
Smalley RJ, Antonia RA, 'Comment on 'The local isotropy hypothesis and the turbulent kinetic energy dissipation rate in the atmospheric surface layer' by M. Chamecki and N. L. Dias (October B, 2004, 130, 2733-2752) (letter)', Quarterly Journal of the Royal Meteorological Society, 132 681-684 (2006) [C3]
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2006 |
Burattini P, Lavoie P, Agrawal A, Djenidi L, Antonia RA, 'Power law of decaying homogeneous isotropic turbulence at low Reynolds number.', Phys Rev E Stat Nonlin Soft Matter Phys, 73 066304 (2006)
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2006 |
Orlandi P, Leonardi S, Antonia RA, 'Vortex structures in a rough-wall channel flow and their influence on passive scalar', Fluid Mechanics and its Applications, 79 39-49 (2006)
DNSs of turbulent channel flows with one rough wall and one smooth wall are presented to show how the vorticity field depends on the shape and orientation of the roughness element... [more]
DNSs of turbulent channel flows with one rough wall and one smooth wall are presented to show how the vorticity field depends on the shape and orientation of the roughness elements. The passive scalar is also evaluated. The high correlation coefficients between vorticity and scalar gradients, in the wall layer, emphasize that in all cases flowvisualizations can be used in a laboratory to have a qualitative picture of the modifications of the high- and low-speed streaks. Joint probability density function between vorticity and scalar gradients show how the bursting events affect the scalar distribution. © 2006 Springer.
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2006 |
Agrawal A, Djenidi L, Antonia RA, 'Investigation of flow around a pair of side-by-side square cylinders using the lattice Boltzmann method', Computers and Fluids, 35 1093-1107 (2006) [C1]
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2006 |
Leonardi S, Orlandi P, Djenidi L, Antonia RA, 'Guidelines for modeling a 2D rough wall channel flow', Flow Turbulence and Combustion, 77 41-57 (2006) [C1]
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2006 |
Burattini P, Lavoie PLD, Agrawal A, Djenidi L, Antonia RA, 'Power law of decaying homogeneous isotropic turbulence at low Reynolds number', Physical Review E, 73 (2006) [C1]
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Nova |
2006 |
Leonardi S, Tessicini F, Orlandi P, Antonia RA, 'Direct Numerical and Large-Eddy Simulations of Turbulent Flows over Rough Surfaces', AIAA Journal, 44 2482-2487 (2006) [C1]
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2005 |
Burattini P, Antonia RA, 'The effect of different X-wire calibration schemes on some turbulence statistics', Experiments in Fluids, 38 80-89 (2005) [C1]
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Nova |
2005 |
Rajagopalan SR, Antonia RA, 'Flow around a circular cylinder - structure of the near wake shear layer', Experiments in Fluids, 38 393-402 (2005) [C1]
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2005 |
Leonardi S, Orlandi P, Antonia RA, 'A method for determining the frictional velocity in a turbulent channel flow with roughness on the bottom wall', Experiments in Fluids, 38 796-800 (2005) [C1]
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Nova |
2005 |
Oyewola O, Djenidi L, Antonia RA, 'Spanwise vorticity measurements in a perturbed boundary layer', Experiments in Fluids, 39 152-155 (2005) [C1]
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2005 |
Burattini P, Lavoie PLD, Antonia RA, 'On the normalized turbulent energy dissipation rate', Physics of Fluids, 17 (2005) [C1]
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2005 |
Burattini P, Antonia RA, Danaila L, 'Similarity in the far field of a turbulent round jet', Physics of Fluids, 17 (2005) [C1]
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Nova |
2005 |
Lavoie PLD, Burattini P, Djenidi L, Antonia RA, 'Effect of initial conditions on decaying grid turbulence at low R-gimel', Experiments in Fluids, 39 865-874 (2005) [C1]
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Nova |
2005 |
Burattini P, Antonia RA, Danaila L, 'Scale-by-scale energy budget on the axis of a turbulent round jet', Journal of Turbulence, 6 1-11 (2005) [C1]
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2005 |
Zhou T, Antonia RA, Chua LP, 'Flow and Reynolds number dependencies of one-dimensional vorticity fluctuations', Journal of Turbulence, 6 1-17 (2005) [C1]
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2005 |
Leonardi S, Orlandi P, Antonia RA, 'Reynolds number dependence of a turbulent channel flow with roughness on one wall', 4th International Symposium on Turbulence and Shear Flow Phenomena, 1 165-170 (2005)
Direct Numerical Simulations of turbulent channel flow with square bars on the bottom wall are discussed have been carried out at different Reynolds numbers. The results tend to c... [more]
Direct Numerical Simulations of turbulent channel flow with square bars on the bottom wall are discussed have been carried out at different Reynolds numbers. The results tend to confirm the inappropriateness of the roughness function as an indication of the effect a particular roughness geometry exerts on the flow. Distributions of turbulent intensities support the improvement in global isotropy relative to a smooth-wall.
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2005 |
Agrawal A, Djenidi L, Antonia RA, 'Simulation of gas flow in microchannels with a sudden expansion or contraction', Journal of Fluid Mechanics, 530 135-144 (2005) [C1]
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Nova |
2004 |
Antonia RA, Orlandi P, 'Similarity of decaying isotropic turbulence with a passive scalar', Journal Fluid Mechanics, 505 123-151 (2004) [C1]
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Nova |
2004 |
Oyewola O, Djenidi L, Antonia RA, 'The response of a turbulent boundary layer to concentrated suction applied through a pair of porous wall strips', Journal of Fluids Engineereing, 126 888-890 (2004) [C1]
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2004 |
Leonardi S, Orlandi P, Djenidi L, Antonia RA, 'Structure of turbulent channel flow with square bars on one wall', International Journal of Heat and Fluid Flow, 25 384-392 (2004) [C1]
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2004 |
Burattini P, Antonia RA, Rajagopalan SR, Stephens ML, 'Effect of initial conditions on the near-field development of a round jet', Experiments in Fluids, 37 56-64 (2004) [C1]
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2004 |
Oyewola O, Djenidi L, Antonia RA, 'Influence of localised wall suction on the anisotropy of the Reynolds stress tensor in a turbulent boundary layer', Experiments in Fluids, 37 187-193 (2004) [C1]
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2004 |
Agrawal A, Djenidi L, Antonia RA, 'LIF based detection of low-speed streaks', experiments in fluids, 36 600-603 (2004) [C1]
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2004 |
Danaila L, Antonia RA, Burattini P, 'Progress in studying small-scale turbulence using 'exact' two-point equations', New Journal of Physics, 6 2-23 (2004) [C1]
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Nova |
2004 |
Orlandi P, Antonia RA, 'Dependence of a passive scalar in decaying isotropic turbulence on the reynolds and schmidt numbers using the EDQNM model', Journal of Turbulence, 5 1-13 (2004) [C1]
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2004 |
Antonia RA, Smalley RJ, Zhou T, Anselmet F, Danaila L, 'Similarity solution of temperature structure functions in decaying homogenous isotropic turbulence', Physical Review E, 69 1630501-1630511 (2004) [C1]
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2003 |
Djenidi L, Antonia RA, Savill AM, 'A numerical study of drag reduction by mini-belts in a smooth wall turbulent boundary layer', The Aeronautical Journal, Paper No.2728 (2003) [C1]
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2003 |
Antonia RA, Orlandi P, 'Effect of Schmidt number on small-scale passive scalar turbulence', Applied Mechanics Reviews, 56 615-632 (2003) [C2]
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2003 |
Leonardi S, Orlandi P, Smalley RJ, Djenidi L, Antonia RA, 'Direct numerical simulations of turbulent channel flow with transverse square bars on one wall', Journal of Fluid Mechanics, 491 229-238 (2003) [C1]
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Nova |
2003 |
Antonia RA, Smalley RJ, Zhou T, Anselmet F, Danaila L, 'Similarity of energy structure functions in decaying homogeneous isotropic turbulence', Journal of Fluid Mechanics, 487 245-269 (2003) [C1]
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Nova |
2003 |
Olsen JF, Rajagopalan SR, Antonia RA, 'Jet column modes in both a plane jet and a passively modified plane jet subject to acoustic excitation', Experiments in Fluids, 278-287 (2003) [C1]
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2003 |
Oyewola O, Djenidi L, Antonia RA, 'Combined influence of the Reynolds number and localised wall suction on a turbulent boundary layer', Experiments in Fluids, 35 199-206 (2003) [C1]
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2003 |
Zhou T, Antonia RA, Lasserre JJ, Coantic M, Anselmet F, 'Transverse velocity and temperature derivative measurements in grid turbulence', Experiments in Fluids, 34 449-459 (2003) [C1]
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2003 |
Antonia RA, 'Tony Perry: his vision and legacy', EXPERIMENTAL THERMAL AND FLUID SCIENCE, 27 130-131 (2003) |
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2003 |
Antonia RA, 'On estimating mean and instantaneous turbulent energy dissipation rates with hot wires', Experimental Thermal and Fluid Science, 27 151-157 (2003) [C1]
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2003 |
Lemay J, Benaissa A, Antonia RA, 'Correction of cold-wire response for mean temperature dissipation rate measurements', Experimental Thermal and Fluid Science, 27 133-143 (2003) [C1]
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2003 |
Orlandi P, Leonardi S, Tuzi R, Antonia RA, 'Direct numerical simulation of turbulent channel flow with wall velocity disturbances', Physics of Fluids, 15 3587-3601 (2003) [C1]
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2003 |
Antonia RA, Orlandi P, 'On the Batchelor constant in decaying isotropic turbulence', Physics of Fluids, 15 2084-2086 (2003) [C1]
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Nova |
2003 |
Danaila L, Anselmet F, Zhou T, Antonia RA, 'Sur l'evolution du taux moyen de dissipation de l'energie cinetique de la turbulence dans une turbulence de grille', Mecanique & Industries, 415-420 (2003) [C2]
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2002 |
Orlandi P, Antonia RA, 'Dependence of the non-stationary form of Yaglom's equation on the Schmidt number', Journal of Fluid Mechanics, 451 99-108 (2002) [C1]
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Nova |
2002 |
Antonia RA, Zhou T, Romano G, 'Small-scale turbulence characteristics of two-dimensional bluff body wakes', Journal of Fluid Mechanics, 459 67-92 (2002) [C1]
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Nova |
2002 |
Zhou T, Antonia RA, Chua L, 'Performance of a probe for measuring turbulent energy and temperature dissipation rates', Experiments in Fluids, 33 334-345 (2002) [C1]
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2002 |
Antonia RA, Orlandi P, Zhou T, 'Assessment of a three-component vorticity probe in decaying turbulence', Experiments in Fluids, 33 384-390 (2002) [C1]
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2002 |
Antonia RA, Xu G, 'Effect of different initial conditions on a turbulent round free jet', Experiments in Fluids, 33 677-683 (2002) [C1]
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2002 |
Smalley RJ, Leonardi S, Antonia RA, Djenidi L, Orlandi P, 'Reynolds stress anistropy of turbulent rough wall layers', Experiments in Fluids, 33 31-37 (2002) [C1]
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2002 |
Xu G, Antonia RA, 'Effect of initial conditions on the temperature field
of a turbulent round free jet', International Communications in Heat and Mass Transfer, 29 1057-1068 (2002) [C1]
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2002 |
Antonia RA, Zhou T, Danaila L, Anselmet F, 'Scaling of the mean energy dissipation rate equation in grid turbulence', Journal of Turbulence, 3 1-7 (2002) [C1]
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2002 |
Danaila L, Anselmet F, Antonia RA, 'An Overview of the effect of large-scale inhomogeneities on small-scale turbulence', Physics of Fluids, 14 2475-2484 (2002) [C1]
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Nova |
2002 |
Antonia RA, Orlandi P, 'Dependence of the second-order scalar structure function on the Schmidt number', Physics of Fluids, 14 1552-1554 (2002) [C1]
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2001 |
Antonia RA, Smalley RJ, 'Scaling range exponents from w-wire measurements in the atmospheric surface layer', Boundary-Layer Meteorology, 100 439-457 (2001) [C1]
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2001 |
Xu G, Rajagopalan S, Antonia RA, 'Genetic alterrations of microsatellite markers at chromosome 17 in non-small cell lung cancer', Chinese Journal of Cancer Research, 13 181-184 (2001)
Objective: To analyse the microsatellite instability (MI) and loss of heterozygosity (LOH) in non-small cell lung cancer (NSCLC). Methods: MI and LOH at chromosome 17 were checked... [more]
Objective: To analyse the microsatellite instability (MI) and loss of heterozygosity (LOH) in non-small cell lung cancer (NSCLC). Methods: MI and LOH at chromosome 17 were checked in 35 cases of NSCLC tumor-normal paired tissues using four microsatellite markers TP53 (17p13.1), THRA1 (17q11.2-12), D17S579 (17q12-21) and D17S855 (17q21) by PCR based analysis. Mutations of P53 exons 5-8 were also tested using PCR-single strand conformation polymorphism (PCR-SSCP) and PCR-denaturing gradient gel electrophoresis (PCR-DGGE) analysis. Results: 22 of 35 tumors (62.8%) displayed MI or LOH. 14 tumors (40.0%) exhibited MI, 11 tumors (31.4%) exhibited LOH, while 3 tumors (8.6%) exhibited MI and LOH concurrently. 23 tumors (8.6%) exhibited P53 gene mutations. The frequency of MI or LOH was obviously higher in the early-stage (stages I and II, 78.9%) than in the advanced-stage (stage III, 43.8%). However, the frequency of MI or LOH had no difference either between high-grade (75.0%) and low-grade (52.6%) differentiated NSCLC or between the tumors with P53 mutations (59.1%) and those without P53 mutations (69.2%). No relationship was observed between the presence of MI or LOH and the histologic subtype of NSCLC. Conclusion: The results suggest that MI and LOH at chromosome 17 may play a significant role in the development of NSCLC. The high frequency of MI or LOH in the early-stage tumors indicates that these genetic alterations could occur early during NSCLC development. Our data also show that the genetic alterations of microsatellite at chromosome 17 was not associated with P53 gene mutations.
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2001 |
Mi J, Antonia RA, 'Effect of large-scale intermittency and mean shear on scaling-range exponents in a turbulent jet', Physical Review E - Statistical, Nonlinear, and Soft Matter Physics, 64 263021-263028 (2001)
The effects of large-scale intermittency and the mean shear rate on the various scaling range exponents in a turbulent jet were studied. Exponents studied were associated with sec... [more]
The effects of large-scale intermittency and the mean shear rate on the various scaling range exponents in a turbulent jet were studied. Exponents studied were associated with second order structure functions and power spectra of both the longitudinal velocity fluctuations and the passive temperature fluctuations. All exponents were influenced by the intermittency and the mean shear rate. Scalar fluctuation exponents were more sensitive than the longitudinal velocity fluctuation exponents.
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2001 |
Pearson BR, Antonia RA, 'Reynolds-number dependence of turbulent velocity and pressure increments', Journal of Fluid Mechanics, 444 343-382 (2001) [C1]
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2001 |
Romano GP, Antonia RA, 'Longitudinal and transverse structure functions in a turbulent round jet: effect of initial conditions and Reynolds number', Journal of Fluid Mechanics, 436 231-248 (2001) [C1]
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2001 |
Danaila L, Anselmet F, Zhou T, Antonia RA, 'Turbulent energy scale budget equations in a fully developed channel flow', Journal of Fluid Mechanics, 430 87-109 (2001) [C1]
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2001 |
Anselmet F, Antonia RA, Danaila L, 'Turbulent flows and intermittency in laboratory experiments', Planetary and Space Science, 49 1177-1191 (2001) [C1]
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2001 |
Djenidi L, Antonia RA, 'Calculation of the effect of concentrated wall suction on a turbulent boundary layer using a second-order moment closure', International Journal of Heat and Fluid Flow, 22 487-494 (2001) [C1]
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2001 |
Zhou T, Person BR, Antonia RA, 'Comparison between temporal and spatial transverse velocity increments in a turbulent plane jet', Fluid Dyanimics Research, 28 127-138 (2001) [C1] |
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2001 |
Xu G, Antonia RA, Rajagopalan SR, 'Sweeping decorrelation hypothesis in a turbulent round jet', Fluid Dynamics Research, 28 311-321 (2001) [C1]
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2001 |
Antonia RA, Krogstad P-A, 'Turbulance structure in boundary layers over different types of surface roughness', Fluid Dynamics Research, 28 139-157 (2001) [C1]
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2001 |
Antonia RA, Zhao Q, 'Effect of initial conditions on a circular jet', Experiments in Fluids, 31 319-323 (2001) [C1]
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2001 |
Rehab H, Antonia RA, Djenidi L, 'Steamwise evloution of a high-Schmidt-number passive scalar in a turbulent plane wake', Experiments in Fluids, 31 186-192 (2001) [C1]
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2001 |
Smalley RJ, Antonia RA, Djenidi L, 'Self-preservation of rough-wall turbulent boundary layers', European Journal of Mechanics B-Fluids, 20 591-602 (2001) [C1]
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2001 |
Mi J, Antonia RA, 'Effect of large-scale intermittency and mean shear on scaling-range exponents in a turbulent jet', Physical Review E, 64 (2001) [C1]
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2001 |
Antonia RA, Smalley RJ, 'Anaomalous scaling of velocity nad temperature structure functions', Physical Review E, 63 (2001) [C1]
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2000 |
Zhou T, Antonia RA, 'Reynolds number dependence of the small-scale structure of grid turbulence', Journal of Fluid Mechanics, 406 81-107 (2000) [C1]
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2000 |
Xu G, Rajagopalan SR, Antonia RA, 'Approach to isotropy in a smooth wall turbulent boundary layer', Fluid Dynamics Research, 26 1-11 (2000) [C1]
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2000 |
Shivamoggi BK, Antonia RA, 'Isotropic and axisymmetric turbulence of passive scalars', Fluid Dynamics Research, 26 95-104 (2000) [C1]
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2000 |
Xu G, Antonia RA, Rajagopalan SR, 'Scaling of mixed longitudinal velocity-temperature structure functions', Europhysics Letters, 49 452-458 (2000) [C1]
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2000 |
Shivamoggi BK, Antonia RA, 'Probability density function of a passive scalar gradient', Physics Letters A, 274 152-161 (2000) [C1]
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2000 |
Rehab H, Antonia RA, Djenidi L, Mi J, 'Characteristics of fluorescein dye and temperature fluctuations in a turbulent near-wake', Experiments in Fluids, 28 462-470 (2000) [C1]
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2000 |
Zhou T, Antonia RA, Danaila L, Anselmet F, 'Transport equations for the mean energy and temperature dissipation rates in grid turbulence', Experiments in Fluids, 28 143-151 (2000) [C1]
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2000 |
Danaila L, Zhou T, Anselmet F, Antonia RA, 'Calibration of a temperature dissipation probe in decaying grid turbulence', Experiments in Fluids, 28 45-50 (2000) [C1]
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2000 |
Antonia RA, Smalley RJ, 'Velocity and temperature scaling in a rough wall boundary layer', Physical Review E, 62 640-646 (2000) [C1]
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2000 |
Antonia RA, Pearson BR, 'Effect of initial conditions on the mean energy dissipation rate and the scaling exponent', Physical Review E, 62 8086-8090 (2000) [C1]
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2000 |
Zhou T, Antonia RA, 'Approximations for turbulent energy and temperature variance dissipation rates in grid turbulence', Physics of Fluids, 12 335-344 (2000) [C1]
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2000 |
Antonia RA, Zhou T, Xu G, 'Second-order temperature and velocity structure functions: Reynolds number dependence', Physics of Fluids, 12 1509-1517 (2000) [C1]
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2000 |
Xu G, Antonia RA, Rajagopalan SR, 'Scaling of mean temperature dissipation rate', Physics of Fluids, 12 3090-3093 (2000) [C1]
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2000 |
Zhang HJ, Zhou Y, Antonia RA, 'Longitudinal and spanwise vortical structures in a turbulent near wake', Physics of Fluids, 12 2954-2964 (2000) [C1] |
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2000 |
Antonia RA, Zhou T, Danaila L, Anselmet F, 'Streamwise inhomogeneity of decaying grid turbulence', Physics of Fluids, 12 3086-3089 (2000) [C1]
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2000 |
Antonia RA, Pearson BR, Zhou T, 'Reynolds number dependence of second-order velocity structure functions', Physics of Fluids, 12 3000-3006 (2000) [C1]
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2000 |
Antonia RA, Pearson BR, 'Reynolds number dependence of velocity structure functions in a turbulent pipe flow', Flow, Turbulence and Combustion, 64 95-117 (2000) [C1]
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2000 |
Anselmet F, Antonia RA, Ould-Rouis M, 'Relations between third-order and second-order structure functions for axisymmetric turbulence', Journal of Turbulence, 1 003 (2000) [C1]
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2000 |
Zhou T, Antonia RA, Danaila L, Anselmet F, 'Approach to the four-fifths 'law' for grid turbulence', Journal of Turbulence, 1 005 (2000) [C1]
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2000 |
Antonia RA, Krogstad PA, 'Effect of different surface roughnesses on a turbulent boundary layer', Revista Brasileira de Ciencias Mecanicas/Journal of the Brazilian Society of Mechanical Sciences, 22 1-15 (2000)
The classical treatment of rough wall turbulent boundary layers consists in determining the effect the roughness has on the mean velocity profile. This effect is usually described... [more]
The classical treatment of rough wall turbulent boundary layers consists in determining the effect the roughness has on the mean velocity profile. This effect is usually described in terms of the roughness function ¿U+. The general implication is that different roughness geometries with the same ¿U+ will have similar turbulence characteristics, at least at a sufficient distance from the roughness elements. Measurements over two different surface geometries (a mesh roughness and spanwise circular rods regularly spaced in the streamwise direction) with nominally the same ¿U+ indicate significant differences in the Reynolds stresses, especially those involving the wall-normal velocity fluctuation, over the outer region. The differences are such that the Reynolds stress anisotropy is smaller over the mesh roughness than the rod roughness. The Reynolds stress anisotropy is largest for a smooth wall. The small-scale anisotropy and interniitency exhibit much smaller differences when the Taylor microscale Reynolds number and the Kolmogorov-normalized mean shear are nominally the same. There is nonetheless evidence that the small-scale structure over the three-dimensional mesh roughness conforms more closely with isotropy than that over the rod-roughened and smooth walls.
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1999 |
Djenidi L, Elavarasan R, Antonia RA, 'The Turbulent Boundary Layer Over Transverse Square Cavities', Journal of Fluid Mechanics, 395 271-294 (1999) [C1]
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1999 |
Danaila L, Anselmet F, Zhou T, Antonia RA, 'A Generalization of Yaglom's Equation which accounts for the Large-Scale Forcing in Heated Decaying Turbulence', Journal of Fluid Mechanics, 391 359-372 (1999) [C1]
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1999 |
Zhou Y, Tsang WK, Antonia RA, 'Vortical Structures in a Turbulent Far-Wake: Effect of
Reynolds Number', Fluid Dynamics Research, 25 293-314 (1999) [C1]
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1999 |
Antonia RA, Pearson BR, 'Low-Order Velocity Structure Functions in Relatively High Reynolds Number', Europhysics Letters, 48 163-169 (1999) [C1]
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1999 |
Antonia RA, Xu G, Zhou T, 'Reynolds Number Dependence of Low-Order Turbulent Temperature Structure Functions', Europhysics Letters, 48 43-48 (1999) [C1]
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1999 |
Romano GP, Antonia RA, Zhou T, 'Evaluation of LDA Temporal and Spatial Velocity Structure
Functions in a Low Reynolds Number Turbulent Channel Flow', Experiments in Fluids, 27 368-377 (1999) [C1]
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1999 |
Antonia RA, Krogstad PA, 'Surface Roughness Effects in Turbulent Boundary Layers', Experiments in Fluids, 27 450-460 (1999) [C1]
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1999 |
Antonia RA, Shafi HS, 'Small Scale Intermittency in a Rough Wall Turbulent Boundary Layer', Experiments in Fluids, 26 145-152 (1999) [C1]
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1999 |
Zhu Y, Antonia RA, 'Performance of a Three-Component Vorticity Probe in a Turbulent Far-Wake', Experiments in Fluids, 27 21-30 (1999) [C1]
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1999 |
Mi J, Antonia RA, 'Evolution of Centreline Temperature Skewness in a Circular
Cylinder Wake', International Communications in Heat & Mass Transfer, 26 45-53 (1999) [C1]
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1999 |
Zhou Y, Antonia RA, Tsang WK, 'The Effect of the Reynolds Number on the Reynolds Stresses and Vorticity in a Turbulent Far-Wake', Experimental Thermal and Fluid Science, 18 291-298 (1999) [C1]
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1999 |
Antonia RA, Bisset DK, Orlandi P, Pearson BR, 'Reynolds Number Dependence on the SEcond-Order Turbulent Pressure Structure Function', Physics of Fluids, 11 241-243 (1999) [C1]
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1998 |
Pearson BR, Zhou T, Antonia RA, 'Relative scaling exponents of n-th-order velocity and temperature structure functions', Europhysics Letters, 44 156-161 (1998) [C1]
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1998 |
Antonia RA, Mi J, 'Approach Towards Self-Preservation of Turbulent Cylinder and Screen Wakes', Experimental Thermal and Fluid Science, 17 277-284 (1998) [C1]
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1998 |
Cenedese A, Romano GP, Antonia RA, 'A Comment on the "Linear" Law of the Wall for Fully Developed Turbulent Channel Flow', Experiments in Fluids, 25 165-170 (1998) [C1]
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1998 |
Zhou Y, Antonia RA, Tsang WK, 'The Effect of Reynolds Number on a Turbulent Far-Wake', Experiments in Fluids, 25 118-125 (1998) [C1]
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1998 |
Zhou T, Antonia RA, Zhu Y, Orlandi P, Esposito P, 'Performance of a Transverse Vorticity Probe in a Turbulent Channel Flow', Experiments in Fluids, 24 510-517 (1998) [C1]
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1998 |
Bonnet JP, Delville J, Glauser MN, Antonia RA, Bisset DK, Cole DR, et al., 'Collaborative Testing of Eddy Structure Identification Methods in Free Turbulent Shear Flows', Experiments in Fluids, 25 197-225 (1998) [C1]
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1998 |
Rajagopalan SR, Antonia RA, 'Turbulence Reduction in the Mixing Layer of a Plane Jet Using Small Cylinders', Experiments in Fluids, 25 96-103 (1998) [C1]
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1998 |
Rajagopalan SR, Zhou T, Antonia RA, 'Three-component turbulence measurementsusing a four-wire probe', Flow Measurement and Instrumentation, 9 211-216 (1998) [C1]
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1998 |
Antonia RA, Zhou T, Zhu Y, 'Three-Component Vorticity Measurements in a Turbulent Grid Flow', Journal of Fluid Mechanics, 374 29-57 (1998) [C1]
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1998 |
Antonia RA, Pearson BR, 'Comparison Between High-Order Velocity Vector and Temperature Structure', Physical Review E, 57 2463-2466 (1998) [C1]
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1998 |
Antonia RA, Ould-Rouis M, Zhu Y, Anselmet F, 'Transport of Turbulent Vorticity Increments', Physical Review E, 57 5483-5488 (1998) [C1]
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1998 |
Antonia RA, Orlandi P, Romano GP, 'Scaling of Longitudinal Velocity Increments in a Fully Developed Turbulent Channel Flow', Physics of Fluids, 10 3239-3241 (1998) [C1]
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1998 |
Djenidi L, Antonia RA, Hundseid J, Krogstad PA, 'Combined Effect of Wall Suction and Riblets on a Low R Turbulent Boundary Layer', The Aeronautical Journal, 102 53-57 (1998) [C1]
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1998 |
Pearson BR, Elavarasan R, Antonia RA, 'Effect of a Short Roughness Strip on a Turbulent Boundary Layer', Applied Scientific Research, 59 61-75 (1998) [C1]
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1997 |
Antonia RA, Zhou T, Romano GP, 'Second- and third-order longitudinal velocity structure functions in a fully developed turbulent channel flow', PHYSICS OF FLUIDS, 9 3465-3471 (1997)
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1997 |
Antonia RA, Djenidi L, 'Reynolds stress producing motions in smooth and rough wall boundary layers', Advances in Fluid Mechanics, 15 181-199 (1997)
Motions that are responsible for the production and maintenance of the Reynolds shear stress in a turbulent boundary layer may be affected by the Reynolds number and the surface r... [more]
Motions that are responsible for the production and maintenance of the Reynolds shear stress in a turbulent boundary layer may be affected by the Reynolds number and the surface roughness. Evidence for each of these effects is presented, based mainly on experiments carried out in our laboratory. The effects are felt in both inner and outer regions of the layer. The evidence points to the non-universality of the active motion and to the sensitivity of the large scale motion to boundary conditions.
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1997 |
Pearson BR, Elavarasan R, Antonia RA, 'The response of a turbulence boundary layer to a square groove', JOURNAL OF FLUIDS ENGINEERING-TRANSACTIONS OF THE ASME, 119 466-469 (1997)
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1997 |
Djenidi L, Antonia RA, 'Modeling of the Reynolds stress transport equation', AIAA JOURNAL, 35 450-455 (1997)
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1997 |
Shafi HS, Antonia RA, Krogstad PA, 'Heat flux measurements in a turbulent boundary layer on a rough wall', INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER, 40 2989-2993 (1997)
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1997 |
Antonia RA, OuldRouis M, Anselmet F, Zhu Y, 'Analogy between predictions of Kolmogorov and Yaglom', JOURNAL OF FLUID MECHANICS, 332 395-409 (1997)
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1997 |
Shafi HS, Antonia RA, 'Small-scale characteristics of a turbulent boundary layer over a rough wall', JOURNAL OF FLUID MECHANICS, 342 263-293 (1997)
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1997 |
Dubief Y, Djenidi L, Antonia RA, 'The measurement of partial derivative u/partial derivative y in a turbulent boundary layer over a riblet surface', INTERNATIONAL JOURNAL OF HEAT AND FLUID FLOW, 18 183-187 (1997)
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1997 |
Dubief Y, Djenidi L, Antonia RA, 'The measurement of u/ y in a turbulent boundary layer over a riblet surface', International Journal of Heat and Fluid Flow, 18 183-187 (1997)
Statistics of ¿u/¿y have been measured in a turbulent boundary layer over either a smooth wall or a riblet surface using parallel hot wires. Over the riblets, the mean square valu... [more]
Statistics of ¿u/¿y have been measured in a turbulent boundary layer over either a smooth wall or a riblet surface using parallel hot wires. Over the riblets, the mean square value of ¿u/¿y (normalised with smooth wall variables) is smaller than over the smooth wall; the difference increases as the distance to the wall decreases. Also this difference is larger when the riblets operate in a drag-augmenting mode. These changes would reflect changes in the near-wall turbulence structure. Furthermore, on the basis that ¿u/¿y is a major contributor to the spanwise vorticity, the results indicate that, relative to the smooth wall, the mean square spanwise vorticity is reduced near a riblet surface. © 1997 by Elsevier Science Inc.
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1997 |
Shafi HS, Zhu Y, Antonia RA, 'Statistics of partial derivative u/partial derivative y in a turbulent wake', FLUID DYNAMICS RESEARCH, 19 169-183 (1997)
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1997 |
Shafi HS, Zhu Y, Antonia RA, 'Statistics of u/ y in a turbulent wake', Fluid Dynamics Research, 19 169-183 (1997)
The small-scale structure of turbulence is studied by measuring the statistics associated with ¿u/¿y in the turbulent wake behind a circular cylinder for a moderate range of R¿ (6... [more]
The small-scale structure of turbulence is studied by measuring the statistics associated with ¿u/¿y in the turbulent wake behind a circular cylinder for a moderate range of R¿ (60-250). The results indicate both similarities and differences between the statistics of ¿u/¿y and those of ¿u/¿x. The pdf of ¿u/¿y, like that of ¿u/¿x, has long exponential tails which are Reynolds number dependent. The flatness factor of ¿u/¿y is larger than that of ¿u/¿x, implying that ¿u/¿y is more intermittent than ¿u/¿x. The spectrum of (¿u/¿y)2 does not exhibit any inertial range power-law dependence, a behaviour which has previously been observed in the spectra of (¿u/¿x)2. In the inertial range, the autocorrelation of ¿u/¿y displays a r-4/3 behaviour while the autocorrelation of (¿u/¿y)2 is similar to that of (¿u/¿x)2, both yielding the same value for the intermittency exponent µ.
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1997 |
Antonia RA, OuldRouis M, Zhu Y, Anselmet F, 'Fourth-order moments of longitudinal- and transverse-velocity structure functions', EUROPHYSICS LETTERS, 37 85-90 (1997)
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1997 |
Antonia RA, Pearson BR, 'Scaling exponents for turbulent velocity and temperature increments', EUROPHYSICS LETTERS, 40 123-128 (1997)
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1997 |
Sreenivasan KR, Antonia RA, 'The phenomenology of small-scale turbulence', ANNUAL REVIEW OF FLUID MECHANICS, 29 435-472 (1997)
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1997 |
Djenidi L, Dubief Y, Antonia RA, 'Advantages of using a power law in a low R(theta) turbulent boundary layer', EXPERIMENTS IN FLUIDS, 22 348-350 (1997)
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1996 |
Djenidi L, Antonia RA, 'Laser Doppler anemometer measurements of turbulent boundary layer over a riblet surface', AIAA JOURNAL, 34 1007-1012 (1996)
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1996 |
Antonia RA, Zhu Y, Shafi HS, 'Lateral vorticity measurements in a turbulent wake', JOURNAL OF FLUID MECHANICS, 323 173-200 (1996)
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1996 |
OuldRouis M, Antonia RA, Zhu Y, Anselmet F, 'Turbulent pressure structure function', PHYSICAL REVIEW LETTERS, 77 2222-2224 (1996)
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1996 |
Mi J, Antonia RA, 'Vorticity characteristics of the turbulent intermediate wake', EXPERIMENTS IN FLUIDS, 20 383-392 (1996)
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1996 |
Antonia RA, Rajagopalan S, Zhu Y, 'Scaling of mean square vorticity in turbulent flows', EXPERIMENTS IN FLUIDS, 20 393-394 (1996)
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1996 |
Britz D, Antonia RA, 'A comparison of methods of computing power spectra of LDA signals', MEASUREMENT SCIENCE AND TECHNOLOGY, 7 1042-1053 (1996)
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1996 |
Zhu Y, Antonia RA, 'The spatial resolution of hot-wire arrays for the measurement of small-scale turbulence', MEASUREMENT SCIENCE AND TECHNOLOGY, 7 1349-1359 (1996)
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1996 |
Zhu Y, Antonia RA, 'Spatial resolution of a 4-X-wire vorticity probe', MEASUREMENT SCIENCE AND TECHNOLOGY, 7 1492-1497 (1996)
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1996 |
Zhu Y, Antonia RA, Kim J, 'Two-point velocity and vorticity correlations for axisymmetric turbulence', PHYSICS OF FLUIDS, 8 838-840 (1996)
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1996 |
Antonia RA, Shafi HS, Zhu Y, 'A note on the vorticity spectrum', PHYSICS OF FLUIDS, 8 2196-2202 (1996)
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1996 |
Shafi HS, Zhu Y, Antonia RA, 'Intermittency of vorticity in a turbulent shear flow', PHYSICS OF FLUIDS, 8 2245-2247 (1996)
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1996 |
Antonia RA, Zhu Y, Anselmet F, OuldRouis M, 'Comparison between the sum of second-order velocity structure functions and the second-order temperature structure function', PHYSICS OF FLUIDS, 8 3105-3111 (1996)
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1995 |
SHAFI HS, ANTONIA RA, 'ANISOTROPY OF THE REYNOLDS STRESSES IN A TURBULENT BOUNDARY-LAYER ON A ROUGH WALL', EXPERIMENTS IN FLUIDS, 18 213-215 (1995)
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1995 |
CHING CY, DJENIDI L, ANTONIA RA, 'LOW-REYNOLDS-NUMBER EFFECTS IN A TURBULENT BOUNDARY-LAYER', EXPERIMENTS IN FLUIDS, 19 61-68 (1995)
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1995 |
ZHOU Y, ANTONIA RA, 'MEMORY EFFECTS IN A TURBULENT PLANE WAKE', EXPERIMENTS IN FLUIDS, 19 112-120 (1995)
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1995 |
MI J, ANTONIA RA, 'GENERAL RELATION FOR STATIONARY PROBABILITY DENSITY-FUNCTIONS', PHYSICAL REVIEW E, 51 4466-4468 (1995)
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1995 |
ZHU Y, ANTONIA RA, HOSOKAWA I, 'REFINED SIMILARITY HYPOTHESES FOR TURBULENT VELOCITY AND TEMPERATURE-FIELDS', PHYSICS OF FLUIDS, 7 1637-1648 (1995)
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1995 |
MI J, ANTONIA RA, ANSELMET F, 'JOINT STATISTICS BETWEEN TEMPERATURE AND ITS DISSIPATION RATE COMPONENTS IN A ROUND JET', PHYSICS OF FLUIDS, 7 1665-1673 (1995)
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1995 |
ANTONIA RA, ZHU Y, SOKOLOV M, 'EFFECT OF CONCENTRATED WALL SUCTION ON A TURBULENT BOUNDARY-LAYER', PHYSICS OF FLUIDS, 7 2465-2474 (1995)
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1995 |
ZHU Y, ANTONIA RA, 'THE SPATIAL-RESOLUTION OF 2 X-PROBES FOR VELOCITY DERIVATIVE MEASUREMENTS', MEASUREMENT SCIENCE AND TECHNOLOGY, 6 538-549 (1995)
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1995 |
Elavarasan R, Ching CY, Antonia RA, 'Turbulent boundary layer over a smooth wall with widely separated transverse square cavities', APPLIED SCIENTIFIC RESEARCH, 55 227-243 (1995)
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1995 |
ZHU Y, ANTONIA RA, 'EFFECT OF WIRE SEPARATION ON X-PROBE MEASUREMENTS IN A TURBULENT-FLOW', JOURNAL OF FLUID MECHANICS, 287 199-223 (1995)
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1994 |
ZHOU Y, ANTONIA RA, 'EFFECT OF INITIAL CONDITIONS ON VORTICES IN A TURBULENT NEAR WAKE', AIAA JOURNAL, 32 1207-1213 (1994)
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1994 |
ANTONIA RA, ZHU Y, 'INERTIAL RANGE BEHAVIOR OF THE LONGITUDINAL HEAT-FLUX COSPECTRUM', BOUNDARY-LAYER METEOROLOGY, 70 429-434 (1994)
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1994 |
MI J, ANTONIA RA, 'TEMPERATURE DISTRIBUTION WITHIN VORTICES IN THE WAKE OF A CYLINDER', INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER, 37 1048-1050 (1994)
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1994 |
ZHOU Y, ANTONIA RA, 'CRITICAL-POINTS IN A TURBULENT NEAR WAKE', JOURNAL OF FLUID MECHANICS, 275 59-81 (1994)
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1994 |
ANTONIA RA, KIM J, 'LOW-REYNOLDS-NUMBER EFFECTS ON NEAR-WALL TURBULENCE', JOURNAL OF FLUID MECHANICS, 276 61-80 (1994)
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1994 |
KROGSTAD PA, ANTONIA RA, 'STRUCTURE OF TURBULENT BOUNDARY-LAYERS ON SMOOTH AND ROUGH WALLS', JOURNAL OF FLUID MECHANICS, 277 1-21 (1994)
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1994 |
DJENIDI L, ANSELMET F, ANTONIA RA, 'LDA MEASUREMENTS IN A TURBULENT BOUNDARY-LAYER OVER A D-TYPE ROUGH WALL', EXPERIMENTS IN FLUIDS, 16 323-329 (1994)
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1994 |
ANTONIA RA, ZHU Y, KIM J, 'CORRECTIONS FOR SPATIAL VELOCITY DERIVATIVES IN A TURBULENT SHEAR-FLOW', EXPERIMENTS IN FLUIDS, 16 411-413 (1994)
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1994 |
MI J, ANTONIA RA, 'SOME CHECKS OF TAYLOR HYPOTHESIS IN A SLIGHTLY HEATED TURBULENT CIRCULAR JET', EXPERIMENTAL THERMAL AND FLUID SCIENCE, 8 328-335 (1994)
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1994 |
ZHOU Y, ANTONIA RA, 'EFFECT OF INITIAL CONDITIONS ON CHARACTERISTICS OF TURBULENT FAR WAKE', JSME INTERNATIONAL JOURNAL SERIES B-FLUIDS AND THERMAL ENGINEERING, 37 718-725 (1994)
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1994 |
ANTONIA RA, SPALART PR, MARIANI P, 'EFFECT OF SUCTION ON THE NEAR-WALL ANISOTROPY OF A TURBULENT BOUNDARY-LAYER', PHYSICS OF FLUIDS, 6 430-432 (1994)
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1994 |
MI J, ANTONIA RA, 'CORRECTIONS TO TAYLOR HYPOTHESIS IN A TURBULENT CIRCULAR JET', PHYSICS OF FLUIDS, 6 1548-1552 (1994)
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1994 |
ANTONIA RA, DJENIDI L, SPALART PR, 'ANISOTROPY OF THE DISPERSION TENSOR IN A TURBULENT BOUNDARY-LAYER', PHYSICS OF FLUIDS, 6 2475-2479 (1994)
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1994 |
PHANTHIEN N, ANTONIA RA, 'ISOTROPIC CARTESIAN TENSORS OF ARBITRARY EVEN ORDERS AND VELOCITY-GRADIENT CORRELATION-FUNCTIONS', PHYSICS OF FLUIDS, 6 3818-3822 (1994)
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1993 |
Zhou Y, Antonia RA, 'A study of flow properties near critical points (1993)
By applying the phase-plane technique to velocity data in the near-wake of a circular cylinder, three types of critical points are identified. Foci and saddle-points occur most fr... [more]
By applying the phase-plane technique to velocity data in the near-wake of a circular cylinder, three types of critical points are identified. Foci and saddle-points occur most frequently, but a significant number of nodes is also found. Flow topology and properties associated with these points are examined in some detail. While foci and saddle points are associated with maxima of local vorticity and strain rate respectively, nodes are associated with a strong local divergence, indicating significant local three-dimensionality. The interrelationship between critical points is also discussed. (Authors)
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1993 |
ANTONIA RA, RAUPACH MR, 'SPECTRAL SCALING IN A HIGH REYNOLDS-NUMBER LABORATORY BOUNDARY-LAYER', BOUNDARY-LAYER METEOROLOGY, 65 289-306 (1993)
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1993 |
TEITEL M, ANTONIA RA, 'HEAT-TRANSFER IN FULLY-DEVELOPED TURBULENT CHANNEL FLOW - COMPARISON BETWEEN EXPERIMENT AND DIRECT NUMERICAL SIMULATIONS', INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER, 36 1701-1706 (1993)
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1993 |
TEITEL M, ANTONIA RA, 'A STEP CHANGE IN WALL HEAT-FLUX IN A TURBULENT CHANNEL FLOW', INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER, 36 1707-1709 (1993)
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1993 |
ANTONIA RA, MI J, 'TEMPERATURE DISSIPATION IN A TURBULENT ROUND JET', JOURNAL OF FLUID MECHANICS, 250 531-551 (1993)
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1993 |
MATSUMURA M, ANTONIA RA, 'MOMENTUM AND HEAT-TRANSPORT IN THE TURBULENT INTERMEDIATE WAKE OF A CIRCULAR-CYLINDER', JOURNAL OF FLUID MECHANICS, 250 651-668 (1993)
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1993 |
KIM J, ANTONIA RA, 'ISOTROPY OF THE SMALL SCALES OF TURBULENCE AT LOW-REYNOLDS-NUMBER', JOURNAL OF FLUID MECHANICS, 251 219-238 (1993)
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1993 |
ZHOU Y, ANTONIA RA, 'A STUDY OF TURBULENT VORTICES IN THE NEAR WAKE OF A CYLINDER', JOURNAL OF FLUID MECHANICS, 253 643-661 (1993)
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1993 |
RAJAGOPALAN S, ANTONIA RA, 'RMS SPANWISE VORTICITY MEASUREMENTS IN A TURBULENT BOUNDARY-LAYER', EXPERIMENTS IN FLUIDS, 14 142-144 (1993)
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1993 |
DJENIDI L, ANTONIA RA, 'LDA MEASUREMENTS IN LOW REYNOLDS-NUMBER TURBULENT BOUNDARY-LAYER', EXPERIMENTS IN FLUIDS, 14 280-288 (1993)
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1993 |
ANTONIA RA, ZHU Y, KIM J, 'ON THE MEASUREMENT OF LATERAL VELOCITY DERIVATIVES IN TURBULENT FLOWS', EXPERIMENTS IN FLUIDS, 15 65-69 (1993)
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1993 |
ANTONIA RA, KROGSTAD PA, 'SCALING OF THE BURSTING PERIOD IN TURBULENT ROUGH WALL BOUNDARY-LAYERS', EXPERIMENTS IN FLUIDS, 15 82-84 (1993)
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1993 |
ZHU Y, ANTONIA RA, 'TEMPERATURE DISSIPATION MEASUREMENTS IN A FULLY-DEVELOPED TURBULENT CHANNEL FLOW', EXPERIMENTS IN FLUIDS, 15 191-199 (1993)
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1993 |
KROGSTAD PA, ANTONIA RA, BROWNE LWB, 'THE USE OF ORTHOGONAL X-WIRE ARRAYS FOR STRUCTURE INVESTIGATION IN A TURBULENT BOUNDARY-LAYER', EXPERIMENTS IN FLUIDS, 15 231-239 (1993)
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1993 |
ANTONIA RA, ZHOU Y, MATSUMURA M, 'SPECTRAL CHARACTERISTICS OF MOMENTUM AND HEAT-TRANSFER IN THE TURBULENT WAKE OF A CIRCULAR-CYLINDER', EXPERIMENTAL THERMAL AND FLUID SCIENCE, 6 371-375 (1993)
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1993 |
RAJAGOPALAN S, ANTONIA RA, 'STRUCTURE OF THE VELOCITY-FIELD ASSOCIATED WITH THE SPANWISE VORTICITY IN THE WALL REGION OF A TURBULENT BOUNDARY-LAYER', PHYSICS OF FLUIDS A-FLUID DYNAMICS, 5 2502-2510 (1993)
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1993 |
ANTONIA RA, ANSELMET F, FULACHIER L, 'NORMALIZATION BASED ON THE ACTIVE MOTION IN A TURBULENT BOUNDARY-LAYER', PHYSICS OF FLUIDS A-FLUID DYNAMICS, 5 3007-3009 (1993)
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1993 |
Zhou Y, Antonia RA, 'A study of flow properties near critical points (1993)
By applying the phase-plane technique to velocity data in the near-wake of a circular cylinder, three types of critical points are identified. Foci and saddle-points occur most fr... [more]
By applying the phase-plane technique to velocity data in the near-wake of a circular cylinder, three types of critical points are identified. Foci and saddle-points occur most frequently, but a significant number of nodes is also found. Flow topology and properties associated with these points are examined in some detail. While foci and saddle points are associated with maxima of local vorticity and strain rate respectively, nodes are associated with a strong local divergence, indicating significant local three-dimensionality. The interrelationship between critical points is also discussed. (Authors)
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1993 |
ANTONIA RA, MI J, 'CORRECTIONS FOR VELOCITY AND TEMPERATURE DERIVATIVES IN TURBULENT FLOWS', EXPERIMENTS IN FLUIDS, 14 203-208 (1993)
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1993 |
Zhou Y, Antonia RA, 'A study of flow properties near critical points (1993)
By applying the phase-plane technique to velocity data in the near-wake of a circular cylinder, three types of critical points are identified. Foci and saddle-points occur most fr... [more]
By applying the phase-plane technique to velocity data in the near-wake of a circular cylinder, three types of critical points are identified. Foci and saddle-points occur most frequently, but a significant number of nodes is also found. Flow topology and properties associated with these points are examined in some detail. While foci and saddle points are associated with maxima of local vorticity and strain rate respectively, nodes are associated with a strong local divergence, indicating significant local three-dimensionality. The interrelationship between critical points is also discussed. (Authors)
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1992 |
ANTONIA RA, TEITEL M, KIM J, BROWNE LWB, 'LOW-REYNOLDS-NUMBER EFFECTS IN A FULLY-DEVELOPED TURBULENT CHANNEL FLOW', JOURNAL OF FLUID MECHANICS, 236 579-605 (1992)
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1992 |
KROGSTAD PA, ANTONIA RA, BROWNE LWB, 'COMPARISON BETWEEN ROUGH-WALL AND SMOOTH-WALL TURBULENT BOUNDARY-LAYERS', JOURNAL OF FLUID MECHANICS, 245 599-617 (1992)
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1992 |
CHUA LP, ANTONIA RA, 'SPATIAL-ORGANIZATION OF LARGE STRUCTURES IN THE NEAR-FIELD OF A CIRCULAR JET', FLUID DYNAMICS RESEARCH, 9 59-71 (1992)
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1992 |
ZHOU Y, ANTONIA RA, 'CONVECTION VELOCITY-MEASUREMENTS IN A CYLINDER WAKE', EXPERIMENTS IN FLUIDS, 13 63-70 (1992)
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1991 |
Bisset DK, Antonia RA, 'Technical Note - Mean velocity and Reynolds shear stress in a turbulent boundary layer at low Reynolds numbers', AERONAUTICAL J., 95 244-247 (1991)
An eddy viscosity relation for the inner region is combined with an empirical wake function for the outer region of a turbulent boundary layer. The calculated distributions for th... [more]
An eddy viscosity relation for the inner region is combined with an empirical wake function for the outer region of a turbulent boundary layer. The calculated distributions for the mean velocity and Reynolds shear stress are compared with both direct numerical simulation and experimental data in a zero pressure gradient boundary layer, mainly at low Reynolds numbers. The comparison is favourable in both the inner and outer regions of the flow. (A)
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1991 |
Raupach MR, Antonia RA, Rajagopalan S, 'Rough-wall turbulent boundary layers', Applied Mechanics Reviews, 44 1-26 (1991)
This review considers theoretical and experimental knowledge of rough-wall turbulent boundary layers, drawing from both laboratory and atmospheric data. The former apply mainly to... [more]
This review considers theoretical and experimental knowledge of rough-wall turbulent boundary layers, drawing from both laboratory and atmospheric data. The former apply mainly to the region above the roughness sublayer (in which the roughness has a direct dynamical influence) whereas the latter resolve the structure of the roughness sublayer in some detail. Topics considered include the drag properties of rough surfaces as functions of the roughness geometry, the mean and turbulent velocity fields above the roughness sublayer, the properties of the flow close to and within the roughness canopy, and the nature of the organized motion in rough-wall boundary layers. Overall, there is strong support for the hypothesis of wall similarity: At sufficiently high Reynolds numbers, rough-wall and smooth-wall boundary layers have the same turbulence structure above the roughness (or viscous) sublayer, scaling with height, boundary-layer thickness, and friction velocity. © 1991 American Society of Mechanical Engineers.
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1991 |
Antonia RA, Bisset DK, Kim J, 'An eddy viscosity calculation method for a turbulent duct flow', TRANS. ASME - J. FLUIDS ENGINEERING, 113 616-619 (1991)
The mean velocity profile across a fully developed turbulent duct flow is obtained from an eddy viscosity relation combined with an empirical outer region wake function. Results a... [more]
The mean velocity profile across a fully developed turbulent duct flow is obtained from an eddy viscosity relation combined with an empirical outer region wake function. Results are in good agreement with experiments and with direct numerical simulations in the same flow at two Reynolds numbers. In particular, the near-wall trend of the Reynolds shear stress and its variation with Reynolds number are similar to those of the simulations. The eddy viscosity method is more accurate than previous mixing length or implicit function methods. (A)
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1991 |
BISSET DK, ANTONIA RA, 'MEAN VELOCITY AND REYNOLDS SHEAR-STRESS IN A TURBULENT BOUNDARY-LAYER AT LOW REYNOLDS-NUMBERS', AERONAUTICAL JOURNAL, 95 244-247 (1991)
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1991 |
ANTONIA RA, KIM J, 'TURBULENT PRANDTL NUMBER IN THE NEAR-WALL REGION OF A TURBULENT CHANNEL FLOW', INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER, 34 1905-1908 (1991)
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1991 |
ANTONIA RA, KIM J, 'REYNOLDS SHEAR-STRESS AND HEAT-FLUX CALCULATIONS IN A FULLY-DEVELOPED TURBULENT DUCT FLOW', INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER, 34 2013-2018 (1991)
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1991 |
ANTONIA RA, KIM J, BROWNE LWB, 'SOME CHARACTERISTICS OF SMALL-SCALE TURBULENCE IN A TURBULENT DUCT FLOW', JOURNAL OF FLUID MECHANICS, 233 369-388 (1991)
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1991 |
ANTONIA RA, BISSET DK, KIM J, 'AN EDDY VISCOSITY CALCULATION METHOD FOR A TURBULENT DUCT FLOW', JOURNAL OF FLUIDS ENGINEERING-TRANSACTIONS OF THE ASME, 113 616-619 (1991)
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1991 |
ANTONIA RA, 'ORGANIZATION IN A TURBULENT NEAR-WAKE', FLUID DYNAMICS RESEARCH, 7 139-149 (1991)
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1991 |
BROWNE LWB, ZHU Y, ANTONIA RA, 'DISSIPATION ESTIMATES IN TURBULENT FLOWS USING THE ZERO-WIRE-LENGTH TECHNIQUE', EXPERIMENTS IN FLUIDS, 11 197-199 (1991)
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1991 |
TEITEL M, ANTONIA RA, 'COMPARISON BETWEEN OUTER REGIONS OF TURBULENT BOUNDARY-LAYER AND CHANNEL FLOWS', EXPERIMENTS IN FLUIDS, 11 203-204 (1991)
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1991 |
CHUA LP, ANTONIA RA, 'SPECTRAL ANALOGY BETWEEN TEMPERATURE VARIANCE AND TURBULENT ENERGY IN A CIRCULAR JET', INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER, 18 569-579 (1991)
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1991 |
FULACHIER L, ANSELMET F, BENABID T, ANTONIA RA, 'NORMALIZATION FOR A TURBULENT BOUNDARY-LAYER WITH WALL SUCTION', PHYSICS OF FLUIDS A-FLUID DYNAMICS, 3 233-235 (1991)
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1991 |
ANTONIA RA, KIM J, 'SIMILARITY BETWEEN TURBULENT KINETIC-ENERGY AND TEMPERATURE SPECTRA IN THE NEAR-WALL REGION', PHYSICS OF FLUIDS A-FLUID DYNAMICS, 3 989-991 (1991)
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1991 |
SANKARAN R, ANTONIA RA, BISSET DK, SOKOLOV M, 'FLOW PATTERNS AND ORGANIZATION WITHIN A TURBULENT SPOT', PHYSICS OF FLUIDS A-FLUID DYNAMICS, 3 1560-1571 (1991)
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1991 |
BISSET DK, ANTONIA RA, RAUPACH MR, 'TOPOLOGY AND TRANSPORT-PROPERTIES OF LARGE-SCALE ORGANIZED MOTION IN A SLIGHTLY HEATED ROUGH WALL BOUNDARY-LAYER', PHYSICS OF FLUIDS A-FLUID DYNAMICS, 3 2220-2228 (1991)
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1990 |
Bisset DK, Antonia RA, Browne LWB, 'Spatial organization of large structures in the turbulent far wake of a cylinder. (1990)
Instantaneous velocity vector patterns in the turbulent far wake of a circular cylinder were obtained using an array of x-probes aligned in the plane of mean shear. Stream-functio... [more]
Instantaneous velocity vector patterns in the turbulent far wake of a circular cylinder were obtained using an array of x-probes aligned in the plane of mean shear. Stream-function approximations and sectional streamlines were derived. Conditional patterns obtained using different methods for detecting the organized motion are essentially independent of the particular method used. The spatial arrangement of the organized motion about the flow centreline varies in a continuous manner between opposing and alternating modes, the latter being nearly twice as common as the former. Results presented include conditional patterns for the opposing and alternating modes and the relative contributions made by each mode to the Reynolds stresses. A modified Rankine vortex kinematic model, based as much as possible on experimental data and incorporating both modes, yields mean velocity and Reynolds stress distributions which agree well with experiment. A quasi-three-dimensional version of the model implies that large spanwise vortices and shear-aligned double rollers represent the same three-dimensional organized motion from two different viewpoints. (A)
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1990 |
Bisset DK, Antonia RA, Britz D, 'Structure of large-scale vorticity in a turbulent far wake. (1990)
Simultaneous measurements have been made of large-scale approximations of the three components of the vorticity vector in the far wake of a slightly heated cylinder. Measurements ... [more]
Simultaneous measurements have been made of large-scale approximations of the three components of the vorticity vector in the far wake of a slightly heated cylinder. Measurements were made in an open-return low turbulence wind tunnel to investigate the properties of large-scale spanwise vortices and shear-aligned double-roller vortices and the relationship between them. The relationship between vorticity and temperature was also studied. The probability density function of the inclination of the vorticity vector in the (x, y)-plane exhibits a maximum at about 45 degrees in the central part of the wake, and in the (x, z)-plane supports the existence of a concentration of spanwise vorticity near the outer part of the wake. In this region there is considerable correlation between vorticity and temperature. Conditional averages of velocity and temperature fluctuations and vorticity are presented based on two detection methods. The first focused on peaks in the W "SUB x" and W "SUB y" signals, and the second on aspects of the large spanwise structures. (from authors' abstract)
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1990 |
ANTONIA RA, RAJAGOPALAN S, 'DETERMINATION OF DRAG OF A CIRCULAR-CYLINDER', AIAA JOURNAL, 28 1833-1834 (1990)
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1990 |
CHUA LP, ANTONIA RA, 'TURBULENT PRANDTL NUMBER IN A CIRCULAR JET', INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER, 33 331-339 (1990)
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1990 |
ANTONIA RA, BISSET DK, 'SPANWISE STRUCTURE IN THE NEAR-WALL REGION OF A TURBULENT BOUNDARY-LAYER', JOURNAL OF FLUID MECHANICS, 210 437-458 (1990)
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1990 |
ANTONIA RA, BISSET DK, BROWNE LWB, 'EFFECT OF REYNOLDS-NUMBER ON THE TOPOLOGY OF THE ORGANIZED MOTION IN A TURBULENT BOUNDARY-LAYER', JOURNAL OF FLUID MECHANICS, 213 267-286 (1990)
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1990 |
BISSET DK, ANTONIA RA, BROWNE LWB, 'SPATIAL-ORGANIZATION OF LARGE STRUCTURES IN THE TURBULENT FAR WAKE OF A CYLINDER', JOURNAL OF FLUID MECHANICS, 218 439-461 (1990)
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1990 |
BISSET DK, ANTONIA RA, BRITZ D, 'STRUCTURE OF LARGE-SCALE VORTICITY IN A TURBULENT FAR WAKE', JOURNAL OF FLUID MECHANICS, 218 463-482 (1990)
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1990 |
ANTONIA RA, RAJAGOPALAN S, 'PERFORMANCE OF LATERAL VORTICITY PROBE IN A TURBULENT WAKE', EXPERIMENTS IN FLUIDS, 9 118-120 (1990)
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1990 |
KRISHNAMOORTHY LV, WOOD DH, ANTONIA RA, 'MEASUREMENTS OF THE THERMAL WAKE OF A SINGLE HOT-WIRE', EXPERIMENTAL THERMAL AND FLUID SCIENCE, 3 338-345 (1990)
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1990 |
TEITEL M, ANTONIA RA, 'THE INTERACTION REGION OF A TURBULENT DUCT FLOW', PHYSICS OF FLUIDS A-FLUID DYNAMICS, 2 808-813 (1990)
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1990 |
Bisset DK, Antonia RA, Britz D, 'Structure of large-scale vorticity in a turbulent far wake. (1990)
Simultaneous measurements have been made of large-scale approximations of the three components of the vorticity vector in the far wake of a slightly heated cylinder. Measurements ... [more]
Simultaneous measurements have been made of large-scale approximations of the three components of the vorticity vector in the far wake of a slightly heated cylinder. Measurements were made in an open-return low turbulence wind tunnel to investigate the properties of large-scale spanwise vortices and shear-aligned double-roller vortices and the relationship between them. The relationship between vorticity and temperature was also studied. The probability density function of the inclination of the vorticity vector in the (x, y)-plane exhibits a maximum at about 45 degrees in the central part of the wake, and in the (x, z)-plane supports the existence of a concentration of spanwise vorticity near the outer part of the wake. In this region there is considerable correlation between vorticity and temperature. Conditional averages of velocity and temperature fluctuations and vorticity are presented based on two detection methods. The first focused on peaks in the W "SUB x" and W "SUB y" signals, and the second on aspects of the large spanwise structures. (from authors' abstract)
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1990 |
Bisset DK, Antonia RA, Browne LWB, 'Spatial organization of large structures in the turbulent far wake of a cylinder. (1990)
Instantaneous velocity vector patterns in the turbulent far wake of a circular cylinder were obtained using an array of x-probes aligned in the plane of mean shear. Stream-functio... [more]
Instantaneous velocity vector patterns in the turbulent far wake of a circular cylinder were obtained using an array of x-probes aligned in the plane of mean shear. Stream-function approximations and sectional streamlines were derived. Conditional patterns obtained using different methods for detecting the organized motion are essentially independent of the particular method used. The spatial arrangement of the organized motion about the flow centreline varies in a continuous manner between opposing and alternating modes, the latter being nearly twice as common as the former. Results presented include conditional patterns for the opposing and alternating modes and the relative contributions made by each mode to the Reynolds stresses. A modified Rankine vortex kinematic model, based as much as possible on experimental data and incorporating both modes, yields mean velocity and Reynolds stress distributions which agree well with experiment. A quasi-three-dimensional version of the model implies that large spanwise vortices and shear-aligned double rollers represent the same three-dimensional organized motion from two different viewpoints. (A)
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1989 |
CHUA LP, ANTONIA RA, 'FLOW REVERSAL AND INTERMITTENCY OF A TURBULENT JET', AIAA JOURNAL, 27 1494-1499 (1989)
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1989 |
ANTONIA RA, FULACHIER L, 'TOPOLOGY OF A TURBULENT BOUNDARY-LAYER WITH AND WITHOUT WALL SUCTION', JOURNAL OF FLUID MECHANICS, 198 429-451 (1989)
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1989 |
BROWNE LWB, ANTONIA RA, SHAH DA, 'ON THE ORIGIN OF THE ORGANIZED MOTION IN THE TURBULENT FAR-WAKE OF A CYLINDER', EXPERIMENTS IN FLUIDS, 7 475-480 (1989)
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1989 |
BROWNE LWB, ANTONIA RA, CHUA LP, 'VELOCITY VECTOR CONE ANGLE IN TURBULENT FLOWS', EXPERIMENTS IN FLUIDS, 8 13-16 (1989)
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1989 |
ANTONIA RA, BRITZ D, 'PHASE-AVERAGING IN THE TURBULENT FAR-WAKE', EXPERIMENTS IN FLUIDS, 7 138-142 (1989)
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1989 |
BROWNE LWB, ANTONIA RA, CHUA LP, 'CALIBRATION OF X-PROBES FOR TURBULENT-FLOW MEASUREMENTS', EXPERIMENTS IN FLUIDS, 7 201-208 (1989)
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1989 |
ANTONIA RA, BROWNE LWB, SHAH DA, 'INSTANTANEOUS DISSIPATIONS OF TURBULENT ENERGY AND TEMPERATURE IN A WAKE', PHYSICS OF FLUIDS A-FLUID DYNAMICS, 1 1374-1382 (1989)
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1989 |
SHAH DA, ANTONIA RA, 'SCALING OF THE BURSTING PERIOD IN TURBULENT BOUNDARY-LAYER AND DUCT FLOWS', PHYSICS OF FLUIDS A-FLUID DYNAMICS, 1 318-325 (1989)
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1988 |
KRISHNAMOORTHY LV, ANTONIA RA, 'TURBULENT KINETIC-ENERGY BUDGET IN THE NEAR-WALL REGION', AIAA JOURNAL, 26 300-302 (1988)
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1988 |
SANKARAN R, ANTONIA RA, 'INFLUENCE OF A FAVORABLE PRESSURE-GRADIENT ON THE GROWTH OF A TURBULENT SPOT', AIAA JOURNAL, 26 885-887 (1988)
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1988 |
ANTONIA RA, KRISHNAMOORTHY LV, FULACHIER L, 'CORRELATION BETWEEN THE LONGITUDINAL VELOCITY FLUCTUATION AND TEMPERATURE-FLUCTUATION IN THE NEAR-WALL REGION OF A TURBULENT BOUNDARY-LAYER', INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER, 31 723-730 (1988)
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1988 |
ANTONIA RA, BROWNE LWB, SHAH DA, 'CHARACTERISTICS OF VORTICITY FLUCTUATIONS IN A TURBULENT WAKE', JOURNAL OF FLUID MECHANICS, 189 349-365 (1988)
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1988 |
ANTONIA RA, FULACHIER L, KRISHNAMOORTHY LV, BENABID T, ANSELMET F, 'INFLUENCE OF WALL SUCTION ON THE ORGANIZED MOTION IN A TURBULENT BOUNDARY-LAYER', JOURNAL OF FLUID MECHANICS, 190 217-+ (1988)
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1988 |
SANKARAN R, SOKOLOV M, ANTONIA RA, 'SUBSTRUCTURES IN A TURBULENT SPOT', JOURNAL OF FLUID MECHANICS, 197 389-414 (1988)
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1988 |
Antonia RA, Browne LWB, Bisset DK, 'Effect of Reynolds number on the organized motion in a turbulent boundary layer', Proceedings of the International Centre for Heat and Mass Transfer, 488-506 (1988)
Measurements have been made in a zero pressure gradient turbulent boundary layer in an attempt to quantify the influence of Reynolds number on features of the motion, which is org... [more]
Measurements have been made in a zero pressure gradient turbulent boundary layer in an attempt to quantify the influence of Reynolds number on features of the motion, which is organised on a scale comparable to the thickness of the layer, in the plane of main shear. These features have been obtained with an array of eight X-probes aligned in a direction normal to the wall, each probe measuring velocity fluctuations u (streamwise direction) and v (normal to the wall). Information derived from the u and v data includes conventional space-time velocity correlations, instantaneous and conditional particle paths and spanwise vorticity contours. The effect of Reynolds number on the spatial extent of isocorrelation contours is more important for u than v. No significant dependence on Reynolds number is observed for conditional particle paths but contours of conditional spanwise vorticity extend to a larger normalised distance from the wall at small Reynolds number. Contributions of the organised motion to the Reynolds stresses tend to be more important as the Reynolds number decreases.
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1988 |
BROWNE LWB, ANTONIA RA, SHAH DA, 'SELECTION OF WIRES AND WIRE SPACING FOR X-WIRES', EXPERIMENTS IN FLUIDS, 6 286-288 (1988)
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1988 |
BRITZ D, SHAH DA, ANTONIA RA, 'THE FINE-SCALE INTERMITTENCY OF TURBULENCE', PHYSICS OF FLUIDS, 31 1431-1438 (1988)
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1988 |
ANTONIA RA, SHAH DA, BROWNE LWB, 'DISSIPATION AND VORTICITY SPECTRA IN A TURBULENT WAKE', PHYSICS OF FLUIDS, 31 1805-1807 (1988)
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1987 |
Antonia RA, Shah DA, Browne LWB, 'Spectra of velocity derivatives in a turbulent wake.', PHYS. FLUIDS, 30 3455-3462 (1987)
One dimensional spectra was measured in the self preserving wake of a circular cylinder for each of the major velocity derivatives that feature in the average dissipation of turbu... [more]
One dimensional spectra was measured in the self preserving wake of a circular cylinder for each of the major velocity derivatives that feature in the average dissipation of turbulent kinetic energy. The comparison between measured spectra and isotropic calculations indicates that isotropy is approached only at high wavenumbers, especially for spectra of derivatives with respect to lateral directions of lateral velocity fluctuations. This result is discussed in the context of the organized large scale motion.
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1987 |
Browne LWB, Antonia RA, 'The effect of wire length on temperature statistics in a turbulent wake.', EXP. FLUIDS, 5 (1987)
Experiments were conducted in the turbulent wake behind a circular cylinder using wires of varying lengths. Measurements were made in a zero pressure gradient blower type non retu... [more]
Experiments were conducted in the turbulent wake behind a circular cylinder using wires of varying lengths. Measurements were made in a zero pressure gradient blower type non return wind tunnel. Results were plotted showing the effect of wire length on relative errors in temperature statistics. Guidelines, based on these results, are given for making temperature measurements in turbulent flows. (P.M.T.)
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1987 |
Antonia RA, Browne LWB, Fulachier L, 'Average wavelength of organised structures in the turbulent far wake of a cylinder.', EXP. FLUIDS, 5 (1987)
The average wavelength of organised structures in the far wake of a circular cylinder is inferred from several different estimates based primarily on wind tunnel measurements. Spe... [more]
The average wavelength of organised structures in the far wake of a circular cylinder is inferred from several different estimates based primarily on wind tunnel measurements. Spectra of the lateral velocity fluctuation and cross spectra between this fluctuation and the temperature fluctuation, at either the same point or at a different point in space, provide relatively unambiguous estimates of the average wavelength of the structures. Dye photographs in a water tunnel provide a less accurate estimate of the average wavelength of the structures. However, all estimates indicate that the average wavelength of the structures. However, all estimates indicate that the average wavelength increases with streamwise distance, at a rate consistent with the self preserving growth of the wake.
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1987 |
Fulachier L, Benabid T, Anselmet F, Antonia RA, Krishnamoorthy LV, 'Behaviour of coherent structures in a turbulent boundary layer with wall suction. (1987)
Presents results of experiments carried out in both wind and water tunnels into the behaviour of coherent structures in fully turbulent flow. Hot wire anemometers were used. (R.I.... [more]
Presents results of experiments carried out in both wind and water tunnels into the behaviour of coherent structures in fully turbulent flow. Hot wire anemometers were used. (R.I.H.)
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1987 |
Antonia RA, Browne LWB, Bisset DK, 'Topology of organised structures in a turbulent plane wake. (1987)
The velocity vector field associated with the organized motion in the turbulent farwake of a circular cylinder was determined by first identifying spatially coherent temperature f... [more]
The velocity vector field associated with the organized motion in the turbulent farwake of a circular cylinder was determined by first identifying spatially coherent temperature fronts. The emerging topological picture underlines the importance of the diverging separatrix and the saddle point, especially with regard to the entrainment of ambient temperature irrotational fluid. It is also concluded that the organized motion is more efficient at transporting heat than momentum. (from authors' abstract)
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1987 |
SHAH DA, ANTONIA RA, 'SCALING OF WALL SHEAR-STRESS FLUCTUATIONS IN A TURBULENT DUCT FLOW', AIAA JOURNAL, 25 22-29 (1987)
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1987 |
ANTONIA RA, BROWNE LWB, 'CONVENTIONAL AND CONDITIONAL PRANDTL NUMBER IN A TURBULENT PLANE WAKE', INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER, 30 2023-2030 (1987)
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1987 |
KRISHNAMOORTHY LV, ANTONIA RA, 'TEMPERATURE-DISSIPATION MEASUREMENTS IN A TURBULENT BOUNDARY-LAYER', JOURNAL OF FLUID MECHANICS, 176 265-281 (1987)
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1987 |
BROWNE LWB, ANTONIA RA, SHAH DA, 'TURBULENT ENERGY-DISSIPATION IN A WAKE', JOURNAL OF FLUID MECHANICS, 179 307-326 (1987)
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1987 |
ANTONIA RA, BROWNE LWB, BISSET DK, FULACHIER L, 'A DESCRIPTION OF THE ORGANIZED MOTION IN THE TURBULENT FAR WAKE OF A CYLINDER AT LOW REYNOLDS-NUMBER', JOURNAL OF FLUID MECHANICS, 184 423-444 (1987)
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1987 |
MILLER IS, SHAH DA, ANTONIA RA, 'A CONSTANT TEMPERATURE HOT-WIRE ANEMOMETER', JOURNAL OF PHYSICS E-SCIENTIFIC INSTRUMENTS, 20 311-314 (1987)
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1987 |
Antonia RA, Browne LWB, 'Quadrant analysis in the turbulent far-wake of a cylinder', Fluid Dynamics Research, 2 3-14 (1987)
The quadrant analysis technique of Willmarth and Lu (1972) has been used to estimate contributions from the four quadrants to the average momentum and heat transfers in the self-p... [more]
The quadrant analysis technique of Willmarth and Lu (1972) has been used to estimate contributions from the four quadrants to the average momentum and heat transfers in the self-preserving region of a turbulent wake. The importance of sweeps near the wake centreline and of ejections at the edge of the wake becomes clearer when sweeps and ejections are viewed in the context of the topology of the large scale motion. The application of the quadrant analysis to the products of velocity and temperature fluctuations conditioned on the large scale motion, clarified the picture inferred from the conventional quadrant analysis approach by clearly identifying the regions of space which are important for transferring momentum and heat. © 1987.
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1987 |
ANTONIA RA, BROWNE LWB, FULACHIER L, 'SPECTRA OF VELOCITY AND TEMPERATURE-FLUCTUATIONS IN THE INTERMITTENT REGION OF A TURBULENT WAKE', PHYSICOCHEMICAL HYDRODYNAMICS, 8 125-135 (1987)
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1987 |
BRITZ D, ANTONIA RA, 'A COMPUTER ALGORITHM FOR THE IDENTIFICATION OF TEMPERATURE FRONTS IN A TURBULENT SHEAR-FLOW', EXPERIMENTS IN FLUIDS, 5 134-140 (1987)
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1987 |
ANTONIA RA, BRITZ DH, SHAH DA, CHAMBERS AJ, 'ON THE FINE SCALE INTERMITTENCY OF TURBULENCE', EXPERIMENTS IN FLUIDS, 5 282-283 (1987)
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1987 |
ANTONIA RA, BROWNE LWB, FULACHIER L, 'AVERAGE WAVELENGTH OF ORGANIZED STRUCTURES IN THE TURBULENT FAR WAKE OF A CYLINDER', EXPERIMENTS IN FLUIDS, 5 298-304 (1987)
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1987 |
BROWNE LWB, ANTONIA RA, 'THE EFFECT OF WIRE LENGTH ON TEMPERATURE STATISTICS IN A TURBULENT WAKE', EXPERIMENTS IN FLUIDS, 5 426-428 (1987)
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1987 |
ANTONIA RA, SHAH DA, BROWNE LWB, 'THE ORGANIZED MOTION OUTSIDE A TURBULENT WAKE', PHYSICS OF FLUIDS, 30 2040-2045 (1987)
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1987 |
ANTONIA RA, SHAH DA, BROWNE LWB, 'SPECTRA OF VELOCITY DERIVATIVES IN A TURBULENT WAKE', PHYSICS OF FLUIDS, 30 3455-3462 (1987)
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1987 |
Fulachier L, Benabid T, Anselmet F, Antonia RA, Krishnamoorthy LV, 'Behaviour of coherent structures in a turbulent boundary layer with wall suction. (1987)
Presents results of experiments carried out in both wind and water tunnels into the behaviour of coherent structures in fully turbulent flow. Hot wire anemometers were used. (R.I.... [more]
Presents results of experiments carried out in both wind and water tunnels into the behaviour of coherent structures in fully turbulent flow. Hot wire anemometers were used. (R.I.H.)
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1987 |
Antonia RA, Browne LWB, Bisset DK, 'Topology of organised structures in a turbulent plane wake. (1987)
The velocity vector field associated with the organized motion in the turbulent farwake of a circular cylinder was determined by first identifying spatially coherent temperature f... [more]
The velocity vector field associated with the organized motion in the turbulent farwake of a circular cylinder was determined by first identifying spatially coherent temperature fronts. The emerging topological picture underlines the importance of the diverging separatrix and the saddle point, especially with regard to the entrainment of ambient temperature irrotational fluid. It is also concluded that the organized motion is more efficient at transporting heat than momentum. (from authors' abstract)
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1986 |
Chua LP, Antonia RA, 'The turbulent interaction region of a circular jet.', INT. J. HEAT & MASS TRANSFER, 13 (1986)
Measurements are presented for the interaction region of a circular jet with initially laminar boundary layers. These measurements include mean and root mean square velocity and t... [more]
Measurements are presented for the interaction region of a circular jet with initially laminar boundary layers. These measurements include mean and root mean square velocity and temperature distributions on the jet axis as well as the evolution of the probability density function of the temperature fluctuation. The streamwise extent of the interaction region is considerably shorter than that of the plane jet with nominally similar initial conditions. The strength of the interaction is considerably less for the circular jet than for the plane jet. (A)
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1986 |
Antonia RS, Krishnamoorthy LV, Fulachier L, Anselmet F, Benabid T, 'Influence of wall suction on coherent structures in a turbulent boundary layer. (1986)
The effect of wall suction on the structure of a turbulent boundary layer is examined both in a wind tunnel and in a water tunnel. The wind tunnel data show that, in the inner lay... [more]
The effect of wall suction on the structure of a turbulent boundary layer is examined both in a wind tunnel and in a water tunnel. The wind tunnel data show that, in the inner layer, the convection velocity of spatially coherent temperature fronts is significantly increased by suction. In the water tunnel, flow visualizations and wind tunnel data strongly support the stabilizing effect of suction.
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1986 |
ANTONIA RA, 'REYNOLDS-NUMBER DEPENDENCE OF TEMPERATURE STRUCTURE FUNCTIONS IN TURBULENT SHEAR FLOWS', BOUNDARY-LAYER METEOROLOGY, 34 411-414 (1986)
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1986 |
ANTONIA RA, BROWNE LWB, 'HEAT-TRANSPORT IN A TURBULENT PLANE WAKE', INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER, 29 1585-1592 (1986)
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1986 |
ANTONIA RA, ANSELMET F, CHAMBERS AJ, 'ASSESSMENT OF LOCAL ISOTROPY USING MEASUREMENTS IN A TURBULENT PLANE JET', JOURNAL OF FLUID MECHANICS, 163 365-391 (1986)
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1986 |
ANTONIA RA, BROWNE LWB, 'ANISOTROPY OF THE TEMPERATURE DISSIPATION IN A TURBULENT WAKE', JOURNAL OF FLUID MECHANICS, 163 393-403 (1986)
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1986 |
SOKOLOV M, ANTONIA RA, CHAMBERS AJ, 'A TURBULENT SPOT IN A TWO-DIMENSIONAL DUCT', JOURNAL OF FLUID MECHANICS, 166 211-225 (1986)
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1986 |
ANTONIA RA, CHAMBERS AJ, BRITZ D, BROWNE LWB, 'ORGANIZED STRUCTURES IN A TURBULENT PLANE JET - TOPOLOGY AND CONTRIBUTION TO MOMENTUM AND HEAT-TRANSPORT', JOURNAL OF FLUID MECHANICS, 172 211-229 (1986)
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1986 |
Britz D, Antonia RA, 'A multipoint method for detecting coherent features in a turbulent shear flow', Fluid Dynamics Research, 1 93-106 (1986)
A technique is presented for the computer detection of temperature fronts in a turbulent shear flow. The detection variable is the product, averaged over a given duration, of temp... [more]
A technique is presented for the computer detection of temperature fronts in a turbulent shear flow. The detection variable is the product, averaged over a given duration, of temperature fluctuations at a given number of spatial locations. Efficient algorithms are developed for computing the product and for determining accurately the instants of detection, aided by simulations, using model temperature fronts. Ensemble averages of temperature and velocity are obtained for the self-preserving region of a turbulent plane jet. © 1986.
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1986 |
CHUA LP, ANTONIA RA, 'THE TURBULENT INTERACTION REGION OF A CIRCULAR JET', INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER, 13 545-558 (1986)
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1986 |
BROWNE LWB, ANTONIA RA, 'REYNOLDS SHEAR-STRESS AND HEAT-FLUX MEASUREMENTS IN A CYLINDER WAKE', PHYSICS OF FLUIDS, 29 709-713 (1986)
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1986 |
BROWNE LWB, ANTONIA RA, BISSET DK, 'COHERENT STRUCTURES IN THE FAR FIELD OF A TURBULENT WAKE', PHYSICS OF FLUIDS, 29 3612-3617 (1986)
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1986 |
SHAH DA, ANTONIA RA, 'ISOTROPIC FORMS OF VORTICITY AND VELOCITY STRUCTURE-FUNCTION EQUATIONS IN SEVERAL TURBULENT SHEAR FLOWS', PHYSICS OF FLUIDS, 29 4016-4024 (1986)
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1986 |
Shah DA, Browne LWB, Antonia RA, 'Reynolds number dependence of a turbulent duct flow. (1986)
Different statistics of the longitudinal velocity fluctuation have been measured in the outer region of a fully developed turbulent duct flow over a large (two decade) Reynolds nu... [more]
Different statistics of the longitudinal velocity fluctuation have been measured in the outer region of a fully developed turbulent duct flow over a large (two decade) Reynolds number range. Whereas high order moments and spectra continue to evolve slowly at the highest Reynolds number, the mean VITA period and VITA ensemble averages, when scaled on outer variables, are approximately constant provided the Reynolds number is sufficiently large. This proviso has to be taken into account when studying the scaling of the bursting frequency in the near wall region.
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1986 |
Antonia RS, Krishnamoorthy LV, Fulachier L, Anselmet F, Benabid T, 'Influence of wall suction on coherent structures in a turbulent boundary layer. (1986)
The effect of wall suction on the structure of a turbulent boundary layer is examined both in a wind tunnel and in a water tunnel. The wind tunnel data show that, in the inner lay... [more]
The effect of wall suction on the structure of a turbulent boundary layer is examined both in a wind tunnel and in a water tunnel. The wind tunnel data show that, in the inner layer, the convection velocity of spatially coherent temperature fronts is significantly increased by suction. In the water tunnel, flow visualizations and wind tunnel data strongly support the stabilizing effect of suction.
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1985 |
CHAMBERS AJ, ANTONIA RA, FULACHIER L, 'TURBULENT PRANDTL NUMBER AND SPECTRAL CHARACTERISTICS OF A TURBULENT MIXING LAYER', INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER, 28 1461-1468 (1985)
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1985 |
ANTONIA RA, 'ON A HEAT-TRANSPORT MODEL FOR A TURBULENT PLANE JET', INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER, 28 1805-1812 (1985)
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1985 |
Krishnamoorthy IV, Wood DH, Antonia RA, Chambers AJ, 'Effect of wire diameter and overheat ratio near a conducting wall.', EXP. FLUIDS, 3 (1985)
The influence on several hot wire measurements of the diameter d and overheat ratio a of a wire placed near a conducting wall in a turbulent boundary layer is investigated. These ... [more]
The influence on several hot wire measurements of the diameter d and overheat ratio a of a wire placed near a conducting wall in a turbulent boundary layer is investigated. These measurements include the mean velocity and second, third and fourth order moments of the longitudinal velocity fluctuation u. A decrease in either d or a reduces the departure of the measured mean velocity from the expected linear sublayer value. The measured influence of d and a precludes the use of a universal correction for the mean velocity. There is no influence of a on the rms, skewness and flatness factors of u. Only a small increase is found in the skewness and flatness factors of u when d is decreased. (A)
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1985 |
Krishnamoorthy LV, Wood DH, Antonia RA, 'The temperature field of a hot-wire adjacent to a conducting wall. (1985)
Measurements of the thermal wakes behind single hot wires have been made in both the free stream above a boundary layer and in the region adjacent to the surface where the measure... [more]
Measurements of the thermal wakes behind single hot wires have been made in both the free stream above a boundary layer and in the region adjacent to the surface where the measured mean velocity rises above that given by the sublayer equation. The former results show that enthalpy balances within the wake are accurate to within 20%. As the hot wire is moved toward the wall the much larger reduction in the enthalpy flux indicates a significant heat transfer to the aluminium wall. The concomitant increase in the measured mean velocity appears to be a function of the wire heat transfer rate, at least when the direct effects of the wire diameter can be ignored. (A)
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1985 |
ANTONIA RA, BRITZ D, 'A NOTE ON THE SPECTRUM OF THE TIME STRUCTURE-FUNCTION', ZEITSCHRIFT FUR ANGEWANDTE MATHEMATIK UND MECHANIK, 65 319-321 (1985)
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1985 |
CHAMBERS AJ, ANTONIA RA, SOKOLOV M, 'EVOLUTION OF A TURBULENT SPOT IN THE ENTRANCE REGION OF A DUCT', PHYSICOCHEMICAL HYDRODYNAMICS, 6 751-758 (1985) |
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1985 |
KRISHNAMOORTHY LV, WOOD DH, ANTONIA RA, CHAMBERS AJ, 'EFFECT OF WIRE DIAMETER AND OVERHEAT RATIO NEAR A CONDUCTING WALL', EXPERIMENTS IN FLUIDS, 3 121-127 (1985)
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1985 |
CHAMBERS AJ, ANTONIA RA, BROWNE LWB, 'EFFECT OF SYMMETRY AND ASYMMETRY OF TURBULENT STRUCTURES ON THE INTERACTION REGION OF A PLANE JET', EXPERIMENTS IN FLUIDS, 3 343-348 (1985)
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1985 |
ANTONIA RA, BROWNE LWB, CHAMBERS AJ, 'RELATIONS BETWEEN SPECTRA OF SPATIAL DERIVATIVES OF TEMPERATURE IN A TURBULENT JET', PHYSICS OF FLUIDS, 28 420-423 (1985)
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1985 |
ANSELMET F, ANTONIA RA, 'JOINT STATISTICS BETWEEN TEMPERATURE AND ITS DISSIPATION IN A TURBULENT JET', PHYSICS OF FLUIDS, 28 1048-1054 (1985)
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1985 |
Antonia RA, Britz D, Chambers AJ, 'SIMILARITY BETWEEN VELOCITY & TEMPERATURE FIELDS IN A TURBULENT PLANE JET. (1985)
The similarity between velocity and temperature fields in the self-preserving region of a plane jet is examined by considering spatial contours of ensemble averages of quantities ... [more]
The similarity between velocity and temperature fields in the self-preserving region of a plane jet is examined by considering spatial contours of ensemble averages of quantities formed using velocity u and v and temperature theta fluctuations. These averages were conditioned on the occurrence of temperature fronts observed with the use of a spanwise rake of temperature sensors. Reasonable similarity exists between overall correlation coefficients for u and v and for v and theta . There is also similarity between contributions from the random motion to these coefficients but, in this case, the spatial distribution is quite different than when the coherent contribution is included. Contributions to the Reynolds shear stress, temperature variance and lateral heat flux from coherent and random motions are roughly equal. The random motion makes a significantly larger contribution to the Reynolds normal stresses than does the random motion.
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1985 |
Krishnamoorthy LV, Wood DH, Antonia RA, 'THERMAL WAKE OF A SINGLE HOT-WIRE IN WALL PROXIMITY. 265-271 (1985)
Thermal wake measurements have been made behind single hot wires, both well away from and very close to a conducting wall. Comparison with theoretical distributions highlights the... [more]
Thermal wake measurements have been made behind single hot wires, both well away from and very close to a conducting wall. Comparison with theoretical distributions highlights the transition from a two to a three dimensional wake as the distance from the wire increases. In the absence of a suitable theory, the measurements in wall proximity were analysed using enthalpy balances. The results provide a firm demonstration of the significant heat transfer to the wall that accompanies wall proximity. An implication of the theory, that wall proximity can be correlated using the wire heat transfer rate, is shown to have some experimental support.
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1985 |
Krishnamoorthy LV, Antonia RA, 'TEMPERATURE DISSIPATION NEAR THE WALL OF A TURBULENT BOUNDARY LAYER. (1985)
The three components of the average temperature dissipation have been measured using a pair of parallel cold wires, in an approximately self-preserving thermal layer. Mean squared... [more]
The three components of the average temperature dissipation have been measured using a pair of parallel cold wires, in an approximately self-preserving thermal layer. Mean squared values OVER BAR theta OVER BAR **2//,//y and OVER BAR theta OVER BAR **2//,//z of temperature derivatives in the directions normal to the flow were mainly obtained from the curvature of spatial temperature autocorrelations. The mean squared value OVER BAR theta OVER BAR **2//,//x of the temperature derivative in the flow direction was mainly inferred from the temporal derivative of temperature and Taylor's hypothesis after the latter was verified at a few locations in the flow. A measure of the accuracy of the dissipation measurements is provided by the negligible imbalance in the temperature variance budget measured in the outer flow region.
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1985 |
Krishnamoorthy LV, Wood DH, Antonia RA, 'TEMPERATURE FIELD OF A HOT-WIRE ADJACENT TO A CONDUCTING WALL. (1985)
Measurements of the thermal wakes behind single hot-wires have been made in both the free-stream above a boundary layer and in the region adjacent to the surface where the measure... [more]
Measurements of the thermal wakes behind single hot-wires have been made in both the free-stream above a boundary layer and in the region adjacent to the surface where the measured mean velocity rises above that given by the sublayer equation. The former results show that enthalpy balances within the wake are accurate to within 20%. As the hot-wire is moved toward the wall the much larger reduction in the enthalpy flux indicates a significant heat transfer to the aluminium wall. The concomitant increase in the measured mean velocity appears to be a function of the wire heat transfer rate, at least when the direct effects of the wire diameter can be ignored.
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1985 |
Krishnamoorthy LV, Wood DH, Antonia RA, 'The temperature field of a hot-wire adjacent to a conducting wall. (1985)
Measurements of the thermal wakes behind single hot wires have been made in both the free stream above a boundary layer and in the region adjacent to the surface where the measure... [more]
Measurements of the thermal wakes behind single hot wires have been made in both the free stream above a boundary layer and in the region adjacent to the surface where the measured mean velocity rises above that given by the sublayer equation. The former results show that enthalpy balances within the wake are accurate to within 20%. As the hot wire is moved toward the wall the much larger reduction in the enthalpy flux indicates a significant heat transfer to the aluminium wall. The concomitant increase in the measured mean velocity appears to be a function of the wire heat transfer rate, at least when the direct effects of the wire diameter can be ignored. (A)
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1984 |
ANTONIA RA, CHAMBERS AJ, ANSELMET F, 'FINE SCALE TURBULENCE MEASUREMENTS IN A PLANE JET', PHYSICOCHEMICAL HYDRODYNAMICS, 5 369-382 (1984)
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1984 |
Sreenivasan KR, Antonia RA, Chambers AJ, 'On the variation of the turbulent prandtl number in shear flows', International Communications in Heat and Mass Transfer, 11 497-501 (1984)
Although the rapid distortion formulation proposed by Townsend (1976) qualitatively describes the variation in the turbulent Prandtl number Prt among different shear flows, direct... [more]
Although the rapid distortion formulation proposed by Townsend (1976) qualitatively describes the variation in the turbulent Prandtl number Prt among different shear flows, direct measurements of Prt indicate that the experimental variation of Prt is underestimated by his formulation. © 1984.
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1984 |
ANTONIA RA, HOPFINGER EJ, GAGNE Y, ANSELMET F, 'TEMPERATURE STRUCTURE FUNCTIONS IN TURBULENT SHEAR FLOWS', PHYSICAL REVIEW A, 30 2704-2707 (1984)
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1984 |
ANTONIA RA, BROWNE LWB, BRITZ D, CHAMBERS AJ, 'A COMPARISON OF PROPERTIES OF TEMPORAL AND SPATIAL TEMPERATURE INCREMENTS IN A TURBULENT PLANE JET', PHYSICS OF FLUIDS, 27 87-93 (1984)
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1984 |
RAJAGOPALAN S, ANTONIA RA, 'CONDITIONAL AVERAGES ASSOCIATED WITH THE FINE-STRUCTURE IN A TURBULENT BOUNDARY-LAYER', PHYSICS OF FLUIDS, 27 1966-1973 (1984)
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1984 |
ANTONIA RA, BROWNE LWB, CHAMBERS AJ, 'ON THE SPECTRUM OF THE TRANSVERSE DERIVATIVE OF THE STREAMWISE VELOCITY IN A TURBULENT-FLOW', PHYSICS OF FLUIDS, 27 2628-2631 (1984)
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1984 |
Antonia RA, Chambers AJ, Browne LWB, Rajagopalan S, 'ORGANISED STRUCTURE IN A SLIGHTLY HEATED TURBULENT PLANE JET. 529-534 (1984)
Two-point correlations of temperature fluctuations confirm the existence, in the self-preserving region of a plane jet, of spanwise structures, occurring alternately on opposite s... [more]
Two-point correlations of temperature fluctuations confirm the existence, in the self-preserving region of a plane jet, of spanwise structures, occurring alternately on opposite sides of the centreline. Conditional averages of temperature fluctuations are computed using a selection procedure based on information obtained at several points in space. The averages are compared with those obtained when the selection is based on information at one point in space.
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1984 |
Antonia RA, Britz DH, Shah DA, Chambers AJ, 'ON THE DETECTION OF FINE SCALE INTERMITTENCY IN TURBULENCE. (1984)
The technique of K. N. Rao, R. Narasimha and Badri Narayanan (1971) is tested by applying it to both Gaussian noise and turbulent velocity fluctuation signals. Measurements includ... [more]
The technique of K. N. Rao, R. Narasimha and Badri Narayanan (1971) is tested by applying it to both Gaussian noise and turbulent velocity fluctuation signals. Measurements include the dependences of the pulse frequency and intermittency factor on the magnitude of the threshold and the dependence of the maximum pulse frequency on the centre frequency of the filter. Important differences exist between white noise and turbulent signal distributions. These differences persist when the white noise spectrum is shaped in an attempt to simulate the spectrum of the turbulent velocity fluctuation. Refs.
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1984 |
Antonia RA, Chambers AJ, Anselmet F, 'Fine scale turbulence measurements in a plane jet.', PHYSIOCHEM. HYDRODYN., 5 369-382 (1984)
This paper summarises results for statistics of spatial derivatives of temperature and longitudinal velocity fluctuations in a turbulent plane jet. Relationships between the mean ... [more]
This paper summarises results for statistics of spatial derivatives of temperature and longitudinal velocity fluctuations in a turbulent plane jet. Relationships between the mean square values of either velocity or temperature derivatives violate isotropy. Statistics that reflect the high wavenumber part of the spectrum are consistent with isotropy. The behaviour of autocorrelations of squares of temperature and velocity derivatives and of band pass filtered temperature and velocity fluctuations indicate that the fine scale temperature field is more intermittent that the fine scale velocity field. The contribution is assessed using conditional averages associated with the large scale motion. (A)
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1984 |
CHAMBERS AJ, ANTONIA RA, 'ATMOSPHERIC ESTIMATES OF POWER-LAW EXPONENT-MU AND EXPONENT-MU-THETA', BOUNDARY-LAYER METEOROLOGY, 28 343-352 (1984)
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1984 |
Antonia RA, Rajagopalan S, Fulachier L, 'Comparison of temperature and velocity spectra in a slightly heated turbulent plane jet', AIAA Journal, 22 311-313 (1984)
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1984 |
FULACHIER L, ANTONIA RA, 'SPECTRAL ANALOGY BETWEEN TEMPERATURE AND VELOCITY FLUCTUATIONS IN SEVERAL TURBULENT FLOWS', INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER, 27 987-997 (1984)
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1984 |
BROWNE LWB, ANTONIA RA, CHAMBERS AJ, 'THE INTERACTION REGION OF A TURBULENT PLANE JET', JOURNAL OF FLUID MECHANICS, 149 355-373 (1984)
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1984 |
ANSELMET F, GAGNE Y, HOPFINGER EJ, ANTONIA RA, 'HIGH-ORDER VELOCITY STRUCTURE FUNCTIONS IN TURBULENT SHEAR FLOWS', JOURNAL OF FLUID MECHANICS, 140 63-89 (1984)
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1983 |
Antonia RA, Browne LW, Rajagopalan S, Chambers AJ, 'On the organized motion of a turbulent plane jet', Journal of Fluid Mechanics, 134 49-66 (1983)
Measurements of space-time correlations of longitudinal and normal velocity fluctuations and of temperature fluctuations support the existence of counter-rotating spanwise structu... [more]
Measurements of space-time correlations of longitudinal and normal velocity fluctuations and of temperature fluctuations support the existence of counter-rotating spanwise structures appearing alternately on opposite sides of the jet centreline in the self-preserving region of the flow. The frequency of these structures closely satisfies self-preservation. The asymmetric arrangement of the structures is first observed downstream of the position where the jet mixing layers nominally merge but upstream of the onset of self-preservation. Closer to the jet exit, the space¿time correlations indicate the existence of spanwise structures that are symmetrical about the centreline. © 1983, Cambridge University Press. All rights reserved.
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1983 |
ANTONIA RA, BROWNE LWB, CHAMBERS AJ, RAJAGOPALAN S, 'BUDGET OF THE TEMPERATURE VARIANCE IN A TURBULENT PLANE JET', INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER, 26 41-48 (1983)
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1983 |
ANTONIA RA, BROWNE LWB, RAJAGOPALAN S, CHAMBERS AJ, 'ON THE ORGANIZED MOTION OF A TURBULENT PLANE JET', JOURNAL OF FLUID MECHANICS, 134 49-66 (1983)
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1983 |
ANTONIA RA, BROWNE LWB, 'THE DESTRUCTION OF TEMPERATURE-FLUCTUATIONS IN A TURBULENT PLANE JET', JOURNAL OF FLUID MECHANICS, 134 67-83 (1983)
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1983 |
BROWNE LWB, ANTONIA RA, 'MEASUREMENTS OF TURBULENT PRANDTL NUMBER IN A PLANE JET', JOURNAL OF HEAT TRANSFER-TRANSACTIONS OF THE ASME, 105 663-665 (1983)
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1983 |
ANTONIA RA, CHAMBERS AJ, BROWNE LWB, 'RELATIONS BETWEEN STRUCTURE FUNCTIONS OF VELOCITY AND TEMPERATURE IN A TURBULENT JET', EXPERIMENTS IN FLUIDS, 1 213-219 (1983)
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1983 |
ANTONIA RA, RAJAGOPALAN S, CHAMBERS AJ, 'CONDITIONAL SAMPLING OF TURBULENCE IN THE ATMOSPHERIC SURFACE-LAYER', JOURNAL OF CLIMATE AND APPLIED METEOROLOGY, 22 69-78 (1983)
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1983 |
BROWNE LWB, ANTONIA RA, RAJAGOPALAN S, 'THE SPATIAL DERIVATIVE OF TEMPERATURE IN A TURBULENT-FLOW AND TAYLORS HYPOTHESIS', PHYSICS OF FLUIDS, 26 1222-1227 (1983)
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1983 |
FULACHIER L, ANTONIA RA, 'SPECTRAL RELATIONSHIPS BETWEEN VELOCITY AND TEMPERATURE-FLUCTUATIONS IN TURBULENT SHEAR FLOWS', PHYSICS OF FLUIDS, 26 2105-2108 (1983)
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1983 |
ANTONIA RA, CHAMBERS AJ, ELENA M, 'POINTS OF SYMMETRY IN TURBULENT SHEAR FLOWS', INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER, 10 395-402 (1983)
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1983 |
Fulachier L, Antonia RA, 'Turbulent Reynolds and Péclet numbers re-defined', International Communications in Heat and Mass Transfer, 10 435-439 (1983)
It is suggested that the use of the fluctuating velocity vector ui may yield a more meaningful comparison between turbulent Reynolds and Péclet numbers. © 1983.... [more]
It is suggested that the use of the fluctuating velocity vector ui may yield a more meaningful comparison between turbulent Reynolds and Péclet numbers. © 1983.
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1983 |
BROWNE LWB, ANTONIA RA, CHAMBERS AJ, 'EFFECT OF THE SEPARATION BETWEEN COLD WIRES ON THE SPATIAL DERIVATIVES OF TEMPERATURE IN A TURBULENT-FLOW', BOUNDARY-LAYER METEOROLOGY, 27 129-139 (1983)
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1982 |
ANTONIA RA, CHAMBERS AJ, BRADLEY EF, '3RD-ORDER AND 4TH-ORDER MIXED MOMENTS OF TURBULENT VELOCITY AND TEMPERATURE-FLUCTUATIONS IN THE ATMOSPHERIC SURFACE-LAYER', BOUNDARY-LAYER METEOROLOGY, 22 421-430 (1982)
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1982 |
BRADLEY EF, ANTONIA RA, CHAMBERS AJ, 'STREAMWISE HEAT-FLUX BUDGET IN THE ATMOSPHERIC SURFACE-LAYER', BOUNDARY-LAYER METEOROLOGY, 23 3-15 (1982)
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1982 |
SATYAPRAKASH BR, ANTONIA RA, BRITZ DH, HUSSAIN A, 'USE OF BREAKDOWN COEFFICIENTS IN TURBULENT JETS TO DETERMINE THE UNIVERSAL EXPONENT MU', BOUNDARY-LAYER METEOROLOGY, 24 77-87 (1982)
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1982 |
ANTONIA RA, SATYAPRAKASH BR, HUSSAIN A, 'STATISTICS OF FINE-SCALE VELOCITY IN TURBULENT PLANE AND CIRCULAR JETS', JOURNAL OF FLUID MECHANICS, 119 55-89 (1982)
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1982 |
ANTONIA RA, RAJAGOPALAN S, SUBRAMANIAN CS, CHAMBERS AJ, 'REYNOLDS-NUMBER DEPENDENCE OF THE STRUCTURE OF A TURBULENT BOUNDARY-LAYER', JOURNAL OF FLUID MECHANICS, 121 123-140 (1982)
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1982 |
SUBRAMANIAN CS, RAJAGOPALAN S, ANTONIA RA, CHAMBERS AJ, 'COMPARISON OF CONDITIONAL SAMPLING AND AVERAGING TECHNIQUES IN A TURBULENT BOUNDARY-LAYER', JOURNAL OF FLUID MECHANICS, 123 335-362 (1982)
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1982 |
PHANTHIEN N, ANTONIA RA, 'POWER-LAW BEHAVIOR OF 2ND-ORDER CORRELATION IN ISOTROPIC TURBULENCE', ZEITSCHRIFT FUR ANGEWANDTE MATHEMATIK UND MECHANIK, 62 129-130 (1982)
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1982 |
VANATTA CW, SOKOLOV M, ANTONIA RA, CHAMBERS AJ, 'POTENTIAL FLOW SIGNATURE OF A TURBULENT SPOT', PHYSICS OF FLUIDS, 25 424-428 (1982)
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1982 |
RAJAGOPALAN S, ANTONIA RA, 'USE OF A QUADRANT ANALYSIS TECHNIQUE TO IDENTIFY COHERENT STRUCTURES IN A TURBULENT BOUNDARY-LAYER', PHYSICS OF FLUIDS, 25 949-956 (1982)
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1982 |
SUBRAMANIAN CS, ANTONIA RA, 'A MODEL FOR THE SKEWNESS OF THE TEMPERATURE DERIVATIVE IN A TURBULENT BOUNDARY-LAYER', PHYSICS OF FLUIDS, 25 957-958 (1982)
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1982 |
RAJAGOPALAN S, SUBRAMANIAN CS, ANTONIA RA, CHAMBERS AJ, 'SPANWISE CORRELATION OF TEMPERATURE IN A TURBULENT BOUNDARY-LAYER', PHYSICS OF FLUIDS, 25 1144-1145 (1982)
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1982 |
ANTONIA RA, RAJAGOPALAN S, BROWNE LWB, CHAMBERS AJ, 'CORRELATIONS OF SQUARED VELOCITY AND TEMPERATURE DERIVATIVES IN A TURBULENT PLANE JET', PHYSICS OF FLUIDS, 25 1156-1158 (1982)
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1982 |
Antonia RA, Browne LWB, 'TRANSPORT EQUATION FOR THE DESTRUCTION OF TEMPERATURE FLUCTUATIONS IN A TURBULENT SHEAR FLOW. 175-184 (1982)
The exact transport equation for the dissipation or destruction of temperature fluctuations in a steady, two-dimensional shear flow is briefly discussed from the point of view of ... [more]
The exact transport equation for the dissipation or destruction of temperature fluctuations in a steady, two-dimensional shear flow is briefly discussed from the point of view of the experimenter's ability to measure the important terms. The transport equation for only one component of the destruction, the mean-square streamwise temperature derivative, is considered in more detail. Measurements of several terms of this equation have been made in the self-preserving region of a turbulent plane jet.
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1982 |
Browne LWB, Antonia RA, Rajagopalan S, Chambers AJ, 'Interaction region of a two-dimensional turbulent plane jet in still air. (1982)
The paper describes an experimental study to investigate the velocity and temperature fields in the interaction region of a two dimensional turbulent plane jet in still air. The e... [more]
The paper describes an experimental study to investigate the velocity and temperature fields in the interaction region of a two dimensional turbulent plane jet in still air. The experimental procedure is briefly described and the velocity and temperature variations plotted on graphs. A discussion is made, and conclusions proposed, as the link between the coherent structures observed in the mixing layer and those that were found in the self preserving far field. (A.J.)
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1982 |
ANTONIA RA, CHAMBERS AJ, BRADLEY EF, 'RELATIONSHIPS BETWEEN STRUCTURE FUNCTIONS AND TEMPERATURE RAMPS IN THE ATMOSPHERIC SURFACE-LAYER', BOUNDARY-LAYER METEOROLOGY, 23 395-403 (1982)
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1982 |
BROWNE LWB, ANTONIA RA, 'MEASUREMENTS IN A THERMAL LAMINAR BOUNDARY-LAYER WITH A CONSTANT PRESSURE-GRADIENT', LETTERS IN HEAT AND MASS TRANSFER, 9 179-185 (1982)
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1982 |
ANTONIA RA, SATYAPRAKASH BR, CHAMBERS AJ, 'REYNOLDS-NUMBER DEPENDENCE OF VELOCITY STRUCTURE FUNCTIONS IN TURBULENT SHEAR FLOWS', PHYSICS OF FLUIDS, 25 29-37 (1982)
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1982 |
Antonia RA, Browne LWB, Chambers AJ, 'Use of fine cold-wires for the measurement of dissipation of temperature fluctuations.', DISA INF., 27-30 (1982)
Wollaston wires of different lengths have been used to measure the mean squared temperature derivative on the centreline of a plane jet. Although criteria for selecting wire param... [more]
Wollaston wires of different lengths have been used to measure the mean squared temperature derivative on the centreline of a plane jet. Although criteria for selecting wire parameters indicate that, for the chosen experimental conditions, only wire of length 0.13 mm is strictly adequate, reasonable agreement is obtained between measurements of the mean squared temperature derivative for a relatively wide range of wire dimensions. (A)
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1981 |
BRADLEY EF, ANTONIA RA, CHAMBERS AJ, 'TEMPERATURE STRUCTURE IN THE ATMOSPHERIC SURFACE-LAYER .1. THE BUDGET OF TEMPERATURE VARIANCE', BOUNDARY-LAYER METEOROLOGY, 20 275-292 (1981)
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1981 |
ANTONIA RA, CHAMBERS AJ, BRADLEY EF, 'TEMPERATURE STRUCTURE IN THE ATMOSPHERIC SURFACE-LAYER .2. THE BUDGET OF MEAN CUBE FLUCTUATIONS', BOUNDARY-LAYER METEOROLOGY, 20 293-307 (1981)
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1981 |
BRADLEY EF, ANTONIA RA, CHAMBERS AJ, 'TURBULENCE REYNOLDS-NUMBER AND THE TURBULENT KINETIC-ENERGY BALANCE IN THE ATMOSPHERIC SURFACE-LAYER', BOUNDARY-LAYER METEOROLOGY, 21 183-197 (1981)
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1981 |
PHONGANANT D, CHAMBERS AJ, ANTONIA RA, 'SPATIAL COHERENCE OF TEMPERATURE-FLUCTUATIONS IN THE ATMOSPHERIC SURFACE-LAYER', BOUNDARY-LAYER METEOROLOGY, 21 465-475 (1981)
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1981 |
PHANTHIEN N, ANTONIA RA, RAJAGOPALAN S, 'PERTURBATION SOLUTION FOR FLOW BETWEEN A ROTATING-DISK AND A PARALLEL STATIONARY PLATE', JOURNAL DE MECANIQUE, 20 617-625 (1981)
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1981 |
RAJAGOPALAN S, ANTONIA RA, 'PROPERTIES OF THE LARGE STRUCTURE IN A SLIGHTLY HEATED TURBULENT MIXING LAYER OF A PLANE JET', JOURNAL OF FLUID MECHANICS, 105 261-281 (1981)
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1981 |
ANTONIA RA, CHAMBERS AJ, SOKOLOV M, VANATTA CW, 'SIMULTANEOUS TEMPERATURE AND VELOCITY-MEASUREMENTS IN THE PLANE OF SYMMETRY OF A TRANSITIONAL TURBULENT SPOT', JOURNAL OF FLUID MECHANICS, 108 317-343 (1981)
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1981 |
CHAMBERS AJ, ANTONIA RA, 'WAVE-INDUCED EFFECT ON THE REYNOLDS SHEAR-STRESS AND HEAT-FLUX IN THE MARINE SURFACE-LAYER', JOURNAL OF PHYSICAL OCEANOGRAPHY, 11 116-121 (1981)
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1981 |
ANTONIA RA, BROWNE LWB, CHAMBERS AJ, 'DETERMINATION OF TIME CONSTANTS OF COLD WIRES', REVIEW OF SCIENTIFIC INSTRUMENTS, 52 1382-1385 (1981)
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1981 |
ANTONIA RA, 'CONDITIONAL SAMPLING IN TURBULENCE MEASUREMENT', ANNUAL REVIEW OF FLUID MECHANICS, 13 131-156 (1981)
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1981 |
CHAMBERS AJ, ANTONIA RA, 'TURBULENCE MEASUREMENTS IN THE BOUNDARY-LAYER OVER A SAND WAVE FIELD - COMMENT', JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS, 86 1091-1091 (1981)
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1981 |
Antonia RA, 'Discussion of "application of a second-moment turbulence closure to heat and mass transport in thin shear flows-I. Two-dimensional transport"', International Journal of Heat and Mass Transfer, 24 1747-1748 (1981)
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1981 |
Chambers AJ, Antonia R, 'Wave induced effect on the Reynolds shear stress and heat flux in the marine surface layer.', J. PHYS. OCEANOGR., 11 116-121 (1981)
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1981 |
Antonia RA, Browne LWB, Chambers AJ, 'Determination of time constants of cold wires.', REV. SCI. INSTRUM., 52 (1981)
The time constant of a fine cold wire used as a resistance thermometer can be obtained by a technique which is based on ideas developed for the pulsed-wire technique for velocity ... [more]
The time constant of a fine cold wire used as a resistance thermometer can be obtained by a technique which is based on ideas developed for the pulsed-wire technique for velocity measurement in highly turbulent flows and in regions of flow reversal. The cold wire is placed downstream of, and at right angles to, a wire of larger diameter which is pulsed with a short duration voltage pulse. The response of the cold wire to the change in the temperature of the flow is used to determine the time constant of the wire, once the pulsed wire time constant is known. Frequency responses based on measured time constants for cold wires of 2.5, 1.3, and 0.63 MUm diameters are presented as a function of flow velocity. (A)
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1981 |
ANTONIA RA, CHAMBERS AJ, SATYAPRAKASH BR, 'REYNOLDS-NUMBER DEPENDENCE OF HIGH-ORDER MOMENTS OF THE STREAMWISE TURBULENT VELOCITY DERIVATIVE', BOUNDARY-LAYER METEOROLOGY, 21 159-171 (1981)
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1981 |
SUBRAMANIAN CS, ANTONIA RA, 'RESPONSE OF A TURBULENT BOUNDARY-LAYER TO A SUDDEN DECREASE IN WALL HEAT-FLUX', INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER, 24 1641-1647 (1981)
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1981 |
SUBRAMANIAN CS, ANTONIA RA, 'EFFECT OF REYNOLDS-NUMBER ON A SLIGHTLY HEATED TURBULENT BOUNDARY-LAYER', INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER, 24 1833-1846 (1981)
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1981 |
ANTONIA RA, CHAMBERS AJ, SATYAPRAKASH BR, 'KOLMOGOROV CONSTANTS FOR STRUCTURE FUNCTIONS IN TURBULENT SHEAR FLOWS', QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY, 107 579-589 (1981)
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1981 |
ANTONIA RA, PHANTHIEN N, SATYAPRAKASH BR, 'AUTO-CORRELATION AND SPECTRUM OF DISSIPATION FLUCTUATIONS IN A TURBULENT JET', PHYSICS OF FLUIDS, 24 554-555 (1981)
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1981 |
Britz D, Antonia RA, Chambers AJ, 'CURRENT FLUCTUATIONS AT MERCURY DROP ELECTRODES UNDER INTENSE POLAROGRAPHIC MAXIMUM CONDITIONS.', PCH. Physicochemical hydrodynamics, 2 121-134 (1981)
Current signals at a dropping and a hanging mercury drop electrode were recorded and digitised, for the intense polarographic maximum obtained in 10 mM Hg**2** plus in 0. 1 M HCl ... [more]
Current signals at a dropping and a hanging mercury drop electrode were recorded and digitised, for the intense polarographic maximum obtained in 10 mM Hg**2** plus in 0. 1 M HCl electrolyte. The measured currents show fluctuations typical of unsteady solution streaming. These fluctuations were studied using techniques developed to study the statistics of turbulent fluctuations. Results are more consistent with convection-limited than diffusion-limited mass transport. Conditional spectra of the fluctuations indicate interfacial velocities comparable with the highest previously measured by other workers.
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1980 |
RAJAGOPALAN S, ANTONIA RA, 'CHARACTERISTICS OF A MIXING LAYER OF A TWO-DIMENSIONAL TURBULENT JET', AIAA JOURNAL, 18 1052-1058 (1980)
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1980 |
ANTONIA RA, HUSSAIN A, 'STATISTICS OF FINE-SCALE VELOCITY IN TURBULENT PLANE AND CIRCULAR JETS', BULLETIN OF THE AMERICAN PHYSICAL SOCIETY, 25 1082-1082 (1980) |
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1980 |
ANTONIA RA, CHAMBERS AJ, PHANTHIEN N, 'TAYLORS HYPOTHESIS AND SPECTRA OF VELOCITY AND TEMPERATURE DERIVATIVES IN A TURBULENT SHEAR-FLOW', BOUNDARY-LAYER METEOROLOGY, 19 19-29 (1980)
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1980 |
ANTONIA RA, CHAMBERS AJ, FRIEHE CA, 'NOTE ON THE VISCOUS HEATING TERM IN THE TEMPERATURE VARIANCE EQUATION', BOUNDARY-LAYER METEOROLOGY, 19 269-272 (1980)
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1980 |
ANTONIA RA, PHANTHIEN N, 'SELF-PRESERVATION OF SLIGHTLY HEATED SMALL PERTURBATION JETS AND WAKES IN A PRESSURE-GRADIENT', INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER, 23 1160-1162 (1980)
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1980 |
ANTONIA RA, PHANTHIEN N, CHAMBERS AJ, 'TAYLOR HYPOTHESIS AND THE PROBABILITY DENSITY-FUNCTIONS OF TEMPORAL VELOCITY AND TEMPERATURE DERIVATIVES IN A TURBULENT-FLOW', JOURNAL OF FLUID MECHANICS, 100 193-208 (1980)
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1980 |
ANTONIA RA, CHAMBERS AJ, 'WIND-WAVE-INDUCED DISTURBANCES IN THE MARINE SURFACE-LAYER', JOURNAL OF PHYSICAL OCEANOGRAPHY, 10 611-622 (1980)
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1980 |
PHONGANANT D, ANTONIA RA, CHAMBERS AJ, RAJAGOPALAN S, 'FEATURES OF THE ORGANIZED MOTION IN THE ATMOSPHERIC SURFACE-LAYER', JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS, 85 424-432 (1980)
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1980 |
ANTONIA RA, CHAMBERS AJ, HUSSAIN A, 'ERRORS IN SIMULTANEOUS MEASUREMENTS OF TEMPERATURE AND VELOCITY IN THE OUTER PART OF A HEATED JET', PHYSICS OF FLUIDS, 23 871-874 (1980)
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1980 |
RAJAGOPALAN S, ANTONIA RA, 'INTERACTION BETWEEN LARGE AND SMALL-SCALE MOTIONS IN A TWO-DIMENSIONAL TURBULENT DUCT FLOW', PHYSICS OF FLUIDS, 23 1101-1110 (1980)
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1980 |
RAJAGOPALAN S, ANTONIA RA, 'INVESTIGATION OF NATURAL TRANSITION IN THE INLET REGION OF A TWO-DIMENSIONAL DUCT FLOW', PHYSICS OF FLUIDS, 23 1938-1948 (1980)
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1980 |
SOKOLOV M, ANTONIA RA, CHAMBERS AJ, 'A SIMILARITY TRANSFORMATION FOR A TURBULENT SPOT IN A LAMINAR BOUNDARY-LAYER', PHYSICS OF FLUIDS, 23 2561-2563 (1980)
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1980 |
Phong-Anant D, Antonia RA, Chambers AJ, Rajagopalan S, 'Features of the organized motion in the atmospheric surface layer.', Journal of Geophysical Research, 85 424-432 (1980)
Simultaneous temperature traces at several heights in the first 8 m of the atmospheric surface layer indicate the presence of an organized structure with a spatially coherent upwi... [more]
Simultaneous temperature traces at several heights in the first 8 m of the atmospheric surface layer indicate the presence of an organized structure with a spatially coherent upwind interface characterized by a sharp decrease in temperature. The convecton speed of this interface, obtained by different methods, increases with height and is approximately equal to the local mean wind velocity.- from Authors
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1980 |
Rajagopalan S, Antonia RA, 'Large structure in a heated turbulent mixing layer.', IN: PROC. 7TH AUSTRALASIAN CONF. ON HYDRAULICS & FLUID MECHANICS, PREPRINTS OF PAPERS, (BRISBANE, AUSTRALIA: AUG. 18-22, 1980, 505-508 (1980)
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1980 |
Satyaprakash BR, Antonia RA, 'The fine-scale structure of the velocity field of turbulent jets.', IN: PROC. 7TH AUSTRALASIAN CONF. ON HYDRAULICS & FLUID MECHANICS, PREPRINTS OF PAPERS, (BRISBANE, AUSTRALIA: AUG. 18-22, 1980, 302-305 (1980)
appears in one of the hypotheses of Kolmogorov and Obukhov depends on the method used to determine it but a decrease in u with increasing order of the moment is qualitatively esta... [more]
appears in one of the hypotheses of Kolmogorov and Obukhov depends on the method used to determine it but a decrease in u with increasing order of the moment is qualitatively established by two different methods. The spectral data are consistent with an increase at high frequencies of the spectral density with an increase in the turbulence Reynolds number. Moments, up to order eight and spectral densities of the velocity derivatives have been measured on the centreline of turbulent plane and circular jets. Some of the difficulties encountered in carrying out the measurements are discussed. A study of the effect of the low-pass filter cut-off frequency on the statistics of the derivative indicates that an appropriate value for this cut-off is about 1.75 fSUPn (fSUPn is the Kolmogorov frequency) and not fSUPn as used by a number of previous investigators. The value of the constant u that
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1980 |
Van Atta CW, Sokolov M, Antonia RA, Chambers AJ, 'The potential flow signature of a turbulent spot.', IN: PROC. 7TH AUSTRALASIAN CONF. ON HYDRAULICS & FLUID MECHANICS, PREPRINTS OF PAPERS, (BRISBANE, AUSTRALIA: AUG. 18-22, 1980, 168-171 (1980)
The organised laminar flow disturbance produced in the free stream above a spark-generated turbulent spot in a laminar boundary layer has been measured and the results compared wi... [more]
The organised laminar flow disturbance produced in the free stream above a spark-generated turbulent spot in a laminar boundary layer has been measured and the results compared with a two-dimensional potential flow theory based on integral properties of the structure of the turbulent region within the spot.
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1980 |
Phong-Anant D, Chambers AJ, Antonia RA, 'Vertical and horizontal spatial coherence of temperature fluctuations in the atmospheric surface layer.', IN: PROC. 7TH AUSTRALASIAN CONF. ON HYDRAULICS & FLUID MECHANICS, PREPRINTS OF PAPERS, (BRISBANE, AUSTRALIA: AUG.18-22, 1980), 513-516 (1980)
The temperature signature of the organised large scale motion in the atmospheric surface layer remains coherent and of approximately constant duration with height. Correlation and... [more]
The temperature signature of the organised large scale motion in the atmospheric surface layer remains coherent and of approximately constant duration with height. Correlation and coherent statics of temperature fluctuations associated with this motion were investigated. Estimates of the spatial extent of this organised motion in both horizontal and vertical directions are obtained. (A)
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1980 |
Antonia RA, 'The organized motion in a turbulent boundary layer.', IN: PROC. 7TH AUSTRALASIAN CONF. ON HYDRAULICS & FLUID MECHANICS, PREPRINTS OF PAPERS, (BRISBANE, AUSTRALIA: AUG.18-22, 1980), 155-162 (1980)
Recent experimental results on coherent structures in a turbulent boundary layer at laboratory Reynolds numbers are briefly reviewed. Suggestions for a possible dynamic link betwe... [more]
Recent experimental results on coherent structures in a turbulent boundary layer at laboratory Reynolds numbers are briefly reviewed. Suggestions for a possible dynamic link between the structures in the outer wall regions are also briefly reviewed. Quantitative agreement between signatures of coherent structures obtained using different detection criteria needs to be improved before the contributions of these structures to the average momentum or heat flux can be trusted. (A)
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1980 |
ANTONIA RA, CHAMBERS AJ, 'ON THE CORRELATION BETWEEN TURBULENT VELOCITY AND TEMPERATURE DERIVATIVES IN THE ATMOSPHERIC SURFACE-LAYER', BOUNDARY-LAYER METEOROLOGY, 18 399-410 (1980)
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1980 |
ANTONIA RA, 'BEHAVIOR OF THE TURBULENT PRANDTL NUMBER NEAR THE WALL', INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER, 23 906-908 (1980)
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1980 |
VANATTA CW, ANTONIA RA, 'REYNOLDS-NUMBER DEPENDENCE OF SKEWNESS AND FLATNESS FACTORS OF TURBULENT VELOCITY DERIVATIVES', PHYSICS OF FLUIDS, 23 252-257 (1980)
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1980 |
ANTONIA RA, SATYAPRAKASH BR, HUSSAIN A, 'MEASUREMENTS OF DISSIPATION RATE AND SOME OTHER CHARACTERISTICS OF TURBULENT PLANE AND CIRCULAR JETS', PHYSICS OF FLUIDS, 23 695-700 (1980)
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1979 |
ANTONIA RA, CHAMBERS AJ, PHONGANANT D, RAJAGOPALAN S, 'PROPERTIES OF SPATIAL TEMPERATURE DERIVATIVES IN THE ATMOSPHERIC SURFACE-LAYER', BOUNDARY-LAYER METEOROLOGY, 17 101-118 (1979)
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1979 |
SREENIVASAN KR, ANTONIA RA, BRITZ D, 'LOCAL ISOTROPY AND LARGE STRUCTURES IN A HEATED TURBULENT JET', JOURNAL OF FLUID MECHANICS, 94 745-775 (1979)
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1979 |
BROWNE LWB, ANTONIA RA, 'CALCULATION OF A TURBULENT BOUNDARY-LAYER DOWNSTREAM OF A STEP CHANGE IN SURFACE-TEMPERATURE', JOURNAL OF HEAT TRANSFER-TRANSACTIONS OF THE ASME, 101 144-150 (1979)
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1979 |
ANTONIA RA, CHAMBERS AJ, FRIEHE CA, VANATTA CW, 'TEMPERATURE RAMPS IN THE ATMOSPHERIC SURFACE-LAYER', JOURNAL OF THE ATMOSPHERIC SCIENCES, 36 99-108 (1979)
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1979 |
Antonia RA, Danh HQ, 'Erratum: Structure of temperature fluctuations in a turbulent boundary layer (Physics of Fluids (1977) 20 (1050))', Physics of Fluids, 22 2434 (1979)
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1979 |
ANTONIA RA, BROWNE LWB, 'RELATIONS BETWEEN SURFACE FLUXES AND MEAN PROFILES OF VELOCITY, TEMPERATURE AND CONCENTRATION, DOWNWIND OF A CHANGE IN SURFACE-ROUGHNESS - COMMENT', QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY, 105 313-316 (1979) |
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1979 |
BRADLEY EF, ANTONIA RA, 'STRUCTURE PARAMETERS IN THE ATMOSPHERIC SURFACE-LAYER', QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY, 105 695-705 (1979)
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1979 |
ANTONIA RA, CHAMBERS AJ, PHONGANANT D, RAJAGOPALAN S, SREENIVASAN KR, 'RESPONSE OF ATMOSPHERIC SURFACE-LAYER TURBULENCE TO A PARTIAL SOLAR ECLIPSE', JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS, 84 1689-1692 (1979)
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1979 |
SUBRAMANIAN CS, ANTONIA RA, 'STATISTICAL PROPERTIES OF TEMPERATURE IN THE WALL REGION OF A TURBULENT BOUNDARY-LAYER', TRANSACTIONS OF THE CANADIAN SOCIETY FOR MECHANICAL ENGINEERING, 5 221-224 (1979) |
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1979 |
RAJAGOPALAN S, ANTONIA RA, 'SOME PROPERTIES OF THE LARGE STRUCTURE IN A FULLY-DEVELOPED TURBULENT DUCT FLOW', PHYSICS OF FLUIDS, 22 614-622 (1979)
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1979 |
ANTONIA RA, VANATTA CW, 'SKEWNESS OF SPATIAL DERIVATIVES OF TEMPERATURE IN A TURBULENT BOUNDARY-LAYER', PHYSICS OF FLUIDS, 22 2430-2431 (1979)
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1979 |
Subramanian CS, Antonia RA, 'Some statistical properties of wall turbulence.', IN: CANCAM .79, PROC. SEVENTH CANADIAN CONGRESS OF APPLIED MECHANICS, (SHERBROOKE, CANADA: MAY 27 - JUN. 1, 1979), F. ELLYIN,, 2 , Sherbrooke, Canada, Proc. Seventh Canadian Congress Appl. Mech., 1979 629-630 (1979) |
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1979 |
Antonia RA, Browne LWB, Mulhearn PJ, 'Comments on the paper Relations between surface fluxes and mean profiles of velocity, temperature and concentration, downwind of a change in surface roughness by P. J. Mulhearn (Q.J. 1977, 103, 785 802)', Quarterly Journal of the Royal Meteorological Society, 105 313-317 (1979)
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1978 |
SREENIVASAN KR, ANTONIA RA, 'JOINT PROBABILITY DENSITIES AND QUADRANT CONTRIBUTIONS IN A HEATED TURBULENT ROUND JET', AIAA JOURNAL, 16 867-868 (1978)
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1978 |
SREENIVASAN KR, ANTONIA RA, STEPHENSON SE, 'CONDITIONAL MEASUREMENTS IN A HEATED AXISYMMETRIC TURBULENT MIXING LAYER', AIAA JOURNAL, 16 869-870 (1978)
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1978 |
ANTONIA RA, PHONGANANT D, 'COHERENT STRUCTURE IN ATMOSPHERIC SURFACE-LAYER', BULLETIN OF THE AMERICAN PHYSICAL SOCIETY, 23 1003-1003 (1978) |
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1978 |
Antonia RA, Chambers AJ, Friehe CA, 'Statistical properties of optical refractive index fluctuations in the marine boundary layer', Boundary-Layer Meteorology, 15 243-253 (1978)
The optical refractive index fluctuation has been determined from measurements of turbulent temperature and humidity fluctuations in the atmospheric surface layer over the ocean. ... [more]
The optical refractive index fluctuation has been determined from measurements of turbulent temperature and humidity fluctuations in the atmospheric surface layer over the ocean. Probability density, spectral density and even- and odd-order structure functions of the refractive index fluctuation are presented. The spectral density exhibits a significant '-5/3' inertial subrange as a result of the existence of a '-5/3' subrange in the spectra of temperature and humidity fluctuations and in the temperature-humidity co-spectrum. The behaviour in the inertial subrange of fourth- and sixth-order structure functions of the refractive index is in reasonable agreement with that predicted by the analysis of Antonia and Van Atta (1975, 1978). The third-order structure functions of the refractive index exhibit an approximately linear dependence on separation in the inertial subrange, in agreement with a ramp model for the large coherent structure of the motion. © 1978 D. Reidel Publishing Company.
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1978 |
Antonia RA, Chambers AJ, 'Spectra of temperature derivatives in the atmospheric surface layer', Boundary-Layer Meteorology, 15 341-345 (1978)
Measured spectra of ¿ x, ¿ y, ¿ z, the derivatives of temperature in streamwise, lateral and vertical directions, respectively, indicate that the spectral densities of ¿ z and ¿ y... [more]
Measured spectra of ¿ x, ¿ y, ¿ z, the derivatives of temperature in streamwise, lateral and vertical directions, respectively, indicate that the spectral densities of ¿ z and ¿ y are nearly similar but significantly different from the spectral density of ¿ x. The high-frequency parts of the three spectra satisfy, in a qualitative sense, local isotropy requirements. In the high-frequency end of the inertial subrange, the relative behaviour of spectra of ¿ x, ¿ y and ¿ z is also consistent with local isotropy. © 1978 D. Reidel Publishing Company.
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1978 |
ANTONIA RA, VANATTA CW, 'STRUCTURE FUNCTIONS OF TEMPERATURE-FLUCTUATIONS IN TURBULENT SHEAR FLOWS', JOURNAL OF FLUID MECHANICS, 84 561-580 (1978)
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1978 |
ANTONIA RA, CHAMBERS AJ, RAJAGOPALAN S, SREENIVASAN KR, FRIEHE CA, 'MEASUREMENTS OF TURBULENT FLUXES IN BASS STRAIT', JOURNAL OF PHYSICAL OCEANOGRAPHY, 8 28-37 (1978)
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1978 |
Antonia RA, Danh HQ, 'Comments on "ratio of scalar and velocity dissipation time scales in shear flow turbulence"', Physics of Fluids, 21 2371 (1978)
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1978 |
Antonia RA, Chambers AJ, Rajagopalan S, Screenivasan KR, 'Measurements of turbulent fluxes in Bass Strait.', Journal of Physical Oceanography, 8 28-37 (1978)
Friehe,C Measurements of turbulent momentum, heat and moisture fluxes have been made in Bass Strait from a stable platform, at a height of approximately 5 m above water. Direct me... [more]
Friehe,C Measurements of turbulent momentum, heat and moisture fluxes have been made in Bass Strait from a stable platform, at a height of approximately 5 m above water. Direct measurements of these fluxes are compared with estimates obtained from spectra of velocity, temperature and humidity fluctuations with the use of the inertial dissipation technique. Directly measured momentum and moisture flux values are in reasonable agreement with inertial dissipation values. Thesensible heat flux obtained by the inertial dissipation technique is about twice as large as the directly measured heat flux. The dependence on wind speed of bulk transfer coefficients of momentum, heat and moisture and of variances of velocity and scalar fluctuations is discussed and compared with available data. (A)
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1978 |
ANTONIA RA, CHAMBERS AJ, VANATTA CW, FRIEHE CA, HELLAND KN, 'SKEWNESS OF TEMPERATURE DERIVATIVE IN A HEATED GRID FLOW', PHYSICS OF FLUIDS, 21 509-510 (1978)
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1978 |
ANTONIA RA, DANH HQ, 'RATIO OF SCALAR AND VELOCITY DISSIPATION TIME SCALES IN SHEAR-FLOW TURBULENCE - COMMENT', PHYSICS OF FLUIDS, 21 2371-2371 (1978)
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1978 |
Sreenivasan KR, Antonia RA, 'ON LOCAL ISOTROPY OF SMALL SCALE TEMPERATURE FLUCTUATIONS. (1978)
The measured skewness of the streamwise temperature derivative in both laboratory and atmospheric turbulent flows has been found to be non-zero (and of either sign) and essentiall... [more]
The measured skewness of the streamwise temperature derivative in both laboratory and atmospheric turbulent flows has been found to be non-zero (and of either sign) and essentially independent of Reynolds number, for a sufficiently large value of the Reynolds number. The apparent contradiction of this result with the hypothesis of local isotropy is examined here in the context of accumulating evidence for the presence of a highly organized large scale motion in turbulent shear flows. In the temperature trace, the signature of the large scale motion appears as a 'ramp-like' structure on which small scale fluctuations are superimposed. The measured non-zero skewness of the temperature derivative does not contradict local isotropy, as it appears to be almost entirely due to the non-isotropic large scale structure.
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1978 |
Sreenivasan KR, Chambers AJ, Antonia RA, 'Accuracy of moments of velocity and scalar fluctuations in the atmospheric surface layer', Boundary-Layer Meteorology, 14 341-359 (1978)
A detailed accuracy analysis is presented for moments, up to order four, of both velocity (horizontal u and vertical w) and scalar (temperature ¿ and humidity q) fluctuations, as ... [more]
A detailed accuracy analysis is presented for moments, up to order four, of both velocity (horizontal u and vertical w) and scalar (temperature ¿ and humidity q) fluctuations, as well as of the products uw, w¿ and wq, in the atmospheric surface layer. The high-order moments and integral time scales required for this analysis are evaluated from data obtained at a height of about 5 m above the ocean surface under stability conditions corresponding to Z/L \- -0.05. Measured moments and probability density functions of some of the individual fluctuations show departures from Gaussianity, but these are sufficiently small to enable good estimates to be obtained using Gaussian instead of measured moments. For the products, the assumption of joint Gaussianity for individual fluctuations provides a reasonable, though somewhat conservative, estimate for the integration times required. The concept of Reynolds number similarity implies that differences in integration time requirements for flows at different Reynolds numbers arise exclusively from differences in integral time scales. A first approximation to the integral time scales relevant to atmospheric flows is presented. © 1978 D. Reidel Publishing Company.
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1978 |
Antonia RA, Chambers AJ, 'Note on the temperature ramp structure in the marine surface layer', Boundary-Layer Meteorology, 15 347-355 (1978)
Ensemble average shapes of temperature ¿ and vertical velocity w associated with a 'ramp-like' signature of the temperature signal recorded in the marine surface layer h... [more]
Ensemble average shapes of temperature ¿ and vertical velocity w associated with a 'ramp-like' signature of the temperature signal recorded in the marine surface layer have been obtained with the use of a conditional sampling technique. The resulting shapes support the 'ramp-like' description of temperature and also suggest an approximately linear distribution in the case of w. The sharp decrease in temperature at the upwind end of the ramp coincides with a relatively sharp decrease in vertical velocity. The region of the ramp in the vicinity of the sharp temperature decrease makes a large contribution to the average heat flux in the layer. © 1978 D. Reidel Publishing Company.
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1978 |
ANTONIA RA, DANH HQ, 'LOCAL SIMILARITY MODEL FOR HEAT-FLUX EQUATION IN A TURBULENT BOUNDARY-LAYER', INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER, 21 1002-1005 (1978)
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1978 |
ANTONIA RA, VANATTA CW, 'ACCURACY OF STRUCTURE FUNCTIONS OF TEMPERATURE IN TURBULENT SHEAR FLOWS', PHYSICS OF FLUIDS, 21 1096-1099 (1978)
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1977 |
Antonia RA, 'STRUCTURE OF TEMPERATURE AND VELOCITY FLUCTUATIONS IN THE ATMOSPHERIC SURFACE LAYER. 13-20 (1977)
Temperature and velocity fluctuations have been measured in the atmospheric surface layer over land. The measured probability densities of the longitudinal velocity and temperatur... [more]
Temperature and velocity fluctuations have been measured in the atmospheric surface layer over land. The measured probability densities of the longitudinal velocity and temperature fluctuations in the atmospheric surface layer show significant deviations from the Gaussian density. This is especially true in the case of temperature fluctuations. Velocity and temperature profiles were determined with anemometers and thermocouples.
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1977 |
Danh HQ, Antonia RA, 'HEAT FLUX BALANCE IN A TURBULENT BOUNDARY LAYER. 233-240 (1977)
Measurements are presented of the budgets of the longitudinal and transverse heat flux in a turbulent boundary layer downstream of a step change in surface heat flux. The surface ... [more]
Measurements are presented of the budgets of the longitudinal and transverse heat flux in a turbulent boundary layer downstream of a step change in surface heat flux. The surface is aerodynamically smooth and the boundary layer develops under zero pressure gradient conditions. , Upstream of the step, where the wall heat flux is zero, the turbulent boundary layer is self-preserving while, downstream of the step, the magnitude of the heat flux is small enough for the temperature field to be considered as a passive contaminant of the flow. A brief description is also given of the experimental facilities and conditions.
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1977 |
Danh HQ, Antonia RA, 'STRUCTURE OF TURBULENCE ASSOCIATED WITH AN INTERNAL THERMAL LAYER. (1977)
Statistical properties are presented of velocity and temperature fluctuations associated with an internal thermal layer. This layer is formed when a fully developed turbulent boun... [more]
Statistical properties are presented of velocity and temperature fluctuations associated with an internal thermal layer. This layer is formed when a fully developed turbulent boundary layer is subjected to a step change in surface heat flux. Upstream of the step, the wall heat flux is zero while downstream of the step, the magnitude of the heat flux is small enough for the temperature field to be treated as a passive contaminant of the flow. Individual and joint probability density functions of longitudinal and normal velocity fluctuations and of the temperature fluctuation are presented both in the conventional sense and in the conditional mode, when only the heated or non-heated parts of the flow are considered. For the conditional measurements, the probability density function of temperature fluctuation is used to effectively locate the edge of the thermal interface.
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1977 |
Luxton RE, Antonia RA, Ahmad QA, 'The effects of an external turbulent uniform shear flow on a turbulent boundary layer. (1977)
A summary is presented of experimental results on the effect of an external uniform shear flow on a turbulent boundary layer. Both positively and negatively sheared external strea... [more]
A summary is presented of experimental results on the effect of an external uniform shear flow on a turbulent boundary layer. Both positively and negatively sheared external streams are considered and their influence on the boundary layer is compared with that of an external stream with zero shear but with a turbulence level comparable to that for the sheared freestream. (A)
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1977 |
ANTONIA RA, VANATTA CW, 'STATISTICAL CHARACTERISTICS OF REYNOLDS STRESSES IN A TURBULENT BOUNDARY-LAYER', AIAA JOURNAL, 15 71-75 (1977)
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1977 |
Antonia RA, 'Similarity of atmospheric Reynolds shear stress and heat flux fluctuations over a rough surface', Boundary-Layer Meteorology, 12 351-364 (1977)
Horizontal u and vertical w velocity fluctuations have been measured together with temperature ¿ fluctuations in the atmospheric surface layer, at a small height above a wheat cro... [more]
Horizontal u and vertical w velocity fluctuations have been measured together with temperature ¿ fluctuations in the atmospheric surface layer, at a small height above a wheat crop canopy. Marginal probability density functions are presented for both individual fluctuations u, w, ¿ and for the instantaneous Reynolds stress uw, and heat fluxes w¿ and u¿. Probability density functions of the velocity fluctuations deviate less significantly from the Gaussian form than the probability density of temperature. There appears to be closer similarity between statistics of the instantaneous heat fluxes than between the momentum flux and either of the heat fluxes investigated. The mean momentum flux receives equal contributions from the events referred to as 'ejections' and 'sweeps' in laboratory boundary layers. 'Sweeps' provide the largest contribution to the heat fluxes. © 1977 D. Reidel Publishing Company.
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1977 |
SREENIVASAN KR, ANTONIA RA, 'PROPERTIES OF WALL SHEAR-STRESS FLUCTUATIONS IN A TURBULENT DUCT FLOW', JOURNAL OF APPLIED MECHANICS-TRANSACTIONS OF THE ASME, 44 389-395 (1977)
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1977 |
ANTONIA RA, DANH HQ, PRABHU A, 'RESPONSE OF A TURBULENT BOUNDARY-LAYER TO A STEP CHANGE IN SURFACE HEAT-FLUX', JOURNAL OF FLUID MECHANICS, 80 153-177 (1977)
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1977 |
ANTONIA RA, DANH HQ, 'STRUCTURE OF TEMPERATURE-FLUCTUATIONS IN A TURBULENT BOUNDARY-LAYER', PHYSICS OF FLUIDS, 20 1050-1057 (1977)
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1977 |
SREENIVASAN KR, ANTONIA RA, DANH HQ, 'TEMPERATURE DISSIPATION FLUCTUATIONS IN A TURBULENT BOUNDARY-LAYER', PHYSICS OF FLUIDS, 20 1238-1249 (1977)
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1977 |
LUXTON RE, ANTONIA RA, AHMAD QA, 'FREE STREAM TURBULENCE AND SHEAR EFFECTS ON BOUNDARY-LAYER AND WAKE STRUCTURES', PHYSICS OF FLUIDS, 20 S288-S288 (1977)
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1977 |
SREENIVASAN KR, DANH HQ, ANTONIA RA, 'TEMPERATURE DISSIPATION FLUCTUATIONS IN A TURBULENT BOUNDARY-LAYER', PHYSICS OF FLUIDS, 20 S288-S288 (1977)
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1977 |
ANTONIA RA, SREENIVASAN KR, 'LOG-NORMALITY OF TEMPERATURE DISSIPATION IN A TURBULENT BOUNDARY LAYER', PHYSICS OF FLUIDS, 20 1800-1804 (1977)
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1977 |
SREENIVASAN KR, ANTONIA RA, 'SKEWNESS OF TEMPERATURE DERIVATIVES IN TURBULENT SHEAR FLOWS', PHYSICS OF FLUIDS, 20 1986-1988 (1977)
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1976 |
Bilger RW, Antonia RA, Sreenivasan KR, 'Determination of intermittency from the probability density function of a passive scalar', Physics of Fluids, 19 1471-1474 (1976)
The probability density functions of temperature in the intermittent regions of heated jet and wake flows show a strong spike associated with the temperature of the unheated fluid... [more]
The probability density functions of temperature in the intermittent regions of heated jet and wake flows show a strong spike associated with the temperature of the unheated fluid. The fine structure of this spike fits a Gaussian curve quite closely, and the area under this Gaussian gives an accurate measure of 1-¿ where ¿ is the intermittency factor. The standard deviation of the Gaussian is a measure of the noise due to residual temperature fluctuations in the free-stream and the electronic noise in the measurement system. The accuracy with which the intermittency can be determined is limited by the signal-to-noise ratio. Copyright © 1976 American Institute of Physics.
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1976 |
ANTONIA RA, BILGER RW, 'HEATED ROUND JET IN A CO-FLOWING STREAM', AIAA JOURNAL, 14 1541-1547 (1976)
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1976 |
Antonia RA, Atkinson JD, 'A ramp model for turbulent temperature fluctuations', Physics of Fluids, 19 1273-1278 (1976)
Temperature fluctuations in a turbulent shear flow are modeled by a ramp-like signal on which relatively high frequency Gaussian fluctuations are superimposed. Both linear ramps w... [more]
Temperature fluctuations in a turbulent shear flow are modeled by a ramp-like signal on which relatively high frequency Gaussian fluctuations are superimposed. Both linear ramps with fixed height and length and exponential ramps of variable length are considered. Parameters which characterize the exponential ramps are obtained from experimental data in a heated jet. High order moments of temperature calculated with the use of the ramp model are in reasonable agreement with available experimental measurements. Copyright & 1976 American Institute of Physics.
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1976 |
Ahmad QA, Luxton RE, Antonia RA, Antonia RA, Antonia RA, 'Characteristics of a turbulent boundary layer with an external turbulent uniform shear flow', Journal of Fluid Mechanics, 77 369-396 (1976)
Measurements are presented of both mean and fluctuating velocity components in a turbulent boundary layer subjected to a nearly homogeneous external turbulent shear flow. The Reyn... [more]
Measurements are presented of both mean and fluctuating velocity components in a turbulent boundary layer subjected to a nearly homogeneous external turbulent shear flow. The Reynolds shear stress in the external shear flow is small compared with the wall shear stress. Its transverse mean velocity gradient ¿ (¿ 6 s-l) is also small compared with typical gradients based on outer variables (say Uw/d, where Uwis the value of the linear velocity profile extrapolated to the wall and d is the boundary-layer thickness), but is of the same order as Ut/d (Ur is the friction velocity). The influence of both positive and negative transverse velocity gradients on the turbulent wall layer is investigated over a streamwise region where the normal Reynolds stresses in the external flow are approximately equal and constant in the streamwise direction. In this region, the integral length scale of the external flow is of the same order of magnitude as that of the wall layer. Measurements in the boundary layer are also given for an un-sheared external turbulent flow (¿ = 0) with a turbulence level Tu of 1.5%, approximately the same as that for h = ± 6 s-1. (Tu, is defined as the ratio of the r.m.s. longitudinal velocity fluctuation to Uw.) The measurements are in good agreement with those available in the literature for a similar free-stream turbulence level and show that the external turbulence level and length scale exert a large influence on the turbulence structure in the boundary layer. The additional effect of the external shear on the mean velocity and turbulent energy budget distributions in the inner region of the boundary layer is found to be small. In the outer region, the ¿wake¿ component of the mean velocity defect is lowered by the presence of free-stream turbulence and one extra effect due to the external shear is an increase in the Reynolds shear stress when h is positive and a decrease when h is negative. Another interesting effect due to the shear is the appearance near the edge of the layer of a small but distinct region where the local mean velocity is constant and the Reynolds shear stress is negligible. © 1976, Cambridge University Press. All rights reserved.
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1976 |
Antonia RA, Prabhir A, 'Reynolds shear stress and heat flux balance in a turbulent round jet', AIAA Journal, 14 221-228 (1976)
Measurements are presented of the budgets of the turbulent energy, Reynolds shear stress, and the heat flux in an axisymmetric heated turbulent jet with a coflowing isothermal ext... [more]
Measurements are presented of the budgets of the turbulent energy, Reynolds shear stress, and the heat flux in an axisymmetric heated turbulent jet with a coflowing isothermal external stream. The jet-to-external-velocity ratio is 6.6, and the temperature of the jet is 34°C above that of the ambient temperature external stream. The budgets are obtained for both the conventional and turbulent zone averages of the various quantities. The conventional budgets of the Reynolds shear stress and the axial and radial heat flux show that the production of these quantities is balanced effectively by the terms containing the pressure fluctuations. The turbulent zone budget of the shear stress and radial heat flux show enhanced diffusion of these quantities by the radial velocity fluctuations in the outer part of the jet. The measured values that feature in the budgets together with the distributions, obtained by difference, of the pressure-containing terms are used to test some of the assumptions made by Donaldson for calculating turbulent free shear layers. © 1976 American Institute of Aeronautics and Astronautics, Inc. All rights reserved.
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1976 |
Antonia RA, Danh HQ, Prabhi A, 'Bursts in turbulent shear flows', Physics of Fluids, 19 1680-1686 (1976)
The burst frequency or frequency of regions in a turbulent flow where the energy dissipation is large has been measured in both laboratory and atmospheric shear flows. The laborat... [more]
The burst frequency or frequency of regions in a turbulent flow where the energy dissipation is large has been measured in both laboratory and atmospheric shear flows. The laboratory measurements were made in two slightly heated flows, a boundary layer in zero pressure gradient and an axisymmetric jet with a co-flowing external system. The atmospheric data were obtained in the first few meters above a wheat canopy. For the laboratory data, the burst frequency, as determined from either velocity or temperature signals, is found to be approximately equal to one half the zero crossing frequency of these signals. In the atmosphere, the burst frequency is very roughly twice the zero crossing frequency. The burst intermittency factor and the ratio of the bunt width to Kolmogoroff length scale are found to be very weakly dependent on the Reynolds number. Available data in the literature on the intermittency factor and width of bursts exhibit extensive scatter and conflicting Reynolds number trends. Copyright © 1976 American Institute of Physics.
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1975 |
Antonia RA, Beck RE, 'Turbulent boundary layers with wall injection', AIAA Journal, 13 952-954 (1975)
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1975 |
Ahmad QA, Luxton RE, Antonia RA, 'The behavior of a two-dimensional wake in a uniformly sheared turbulent flow', Journal of Applied Mechanics, Transactions ASME, 42 283-288 (1975)
The behavior of a cylinder wake in a weak uniformly sheared external stream is studied. It is found that the departure of the wake from the linear velocity distribution of the ext... [more]
The behavior of a cylinder wake in a weak uniformly sheared external stream is studied. It is found that the departure of the wake from the linear velocity distribution of the external flow is approximately self preserving. There is a tendency for the wake to grow faster on the ¿high velocity¿ side (where aU/ay has the same sign inside and outside the wake) than on the ¿low velocity¿ side (where the signs of aU/ay are different). This result agrees with the limited evidence on the growth of boundary layers under a uniformly sheared free stream. The turbulence structures on the two sides of the wake appear to behave independently of each other. © 1975 by ASME.
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1975 |
Wood DH, Antonia RA, 'Measurements in a turbulent boundary layer over a d-type surface roughness', Journal of Applied Mechanics, Transactions ASME, 42 591-597 (1975)
Mean velocity and turbulence intensity measurements have been made in a fully developed turbulent boundary layer over a d-type surface roughness. This roughness is characterised b... [more]
Mean velocity and turbulence intensity measurements have been made in a fully developed turbulent boundary layer over a d-type surface roughness. This roughness is characterised by regular two-dimensional elements of square cross section placed one element width apart, with the cavity flow between elements being essentially isolated from the outer flow. The measurements show that this boundary layer closely satisfies the requirement of exact self-preservation. Distribution across the layer of Reynolds normal and shear stresses are closely similar to those found over a smooth surface except for the region immediately above the grooves. This similarity extends to distributions of third and fourth-order moments of longitudinal and normal velocity fluctuations and also to the distribution of turbulent energy dissipation. The present results are compared with those obtained for a k-type or sand grained roughness. © 1975 by ASME.
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1975 |
Antonia RA, Van Atta CW, 'On the correlation between temperature and velocity dissipation fields in a heated turbulent jet', Journal of Fluid Mechanics, 67 273-288 (1975)
A few statistical properties of fine-scale velocity and temperature fluctuations have been measured on the axis of symmetry of a heated turbulent round jet. The probability densit... [more]
A few statistical properties of fine-scale velocity and temperature fluctuations have been measured on the axis of symmetry of a heated turbulent round jet. The probability density of ¿¿/¿x, the streamwise derivative of the temperature fluctuation, is strongly negatively skewed, indicating a lack of isotropy for the fine-scale temperature structure. An estimate of the correlation between the velocity and temperature dissipation fields has been obtained by assuming that the dissipation of velocity and dissipation of temperature can be approximated by (¿¿/¿x)2, where u is the streamwise velocity fluctuation, and (¿¿/¿x)2r respectively. The correlation between the quantities (¿¿/¿x)2r and (¿¿/¿x)2r averages over a volume of linear dimension r, is fairly high and depends on the choice of r. An analysis shows that this correlation plays a vital role in the prediction of high-order structure functions of u and ¿. The assumed lognormality of the probability density of (¿¿/¿x)2r and (¿¿/¿x)2r and of their joint density is found to be reasonable over a range of r corresponding to the inertial subrange. © 1975, Cambridge University Press. All rights reserved.
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1975 |
Antonia RA, Prabhu A, Stephenson SE, 'Conditionally sampled measurements in a heated turbulent jet', Journal of Fluid Mechanics, 72 455-480 (1975)
Measurements of velocity fluctuations u (axial) and v (radial) and temperature fluctuations ¿ averaged over the turbulent zone have been made in a turbulent heated jet with a co-f... [more]
Measurements of velocity fluctuations u (axial) and v (radial) and temperature fluctuations ¿ averaged over the turbulent zone have been made in a turbulent heated jet with a co-flowing stream and compared with the conventionally averaged results. The zone-averaged mean temperature and temperature fluctuation intensity appear to be nearly homogeneously distributed in the outer, intermittent region of the jet. This homogeneity does not apply to the u and v fluctuations. The flatness factor of the temperature within the turbulent part of the flow is remarkably constant throughout the intermittent region. Although the skewness of the turbulent ¿ fluctuations is non-zero, it is smaller than the skewness of the turbulent u and v fluctuations. The average [Formula ommited] of the heat flux over the turbulent zone increases in the intermittent region whereas the zone-averaged momentum flux [Formula ommited] and zone-averaged heat flux [Formula ommited] continuously decrease. This leads to the Prandtl number of the turbulent fluid being smaller than the conventional Prandtl number in the outer part of the flow. A budget for the square of the temperature fluctuations within the turbulent part of the flow indicates a constant distribution of temperature dissipation. The transport of heat by the large-scale structure of the flow is briefly discussed in the light of available experimental information on other turbulent shear flows. © 1975, Cambridge University Press. All rights reserved.
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1975 |
ANTONIA RA, PRABHU A, STEPHENSON SE, 'CONDITIONALLY SAMPLED MEASUREMENTS IN A HEATED TURBULENT JET.', Journal of Fluid Mechanics, 72 (1975)
MEASUREMENTS OF VELOCITY FLUCTUATIONS LUL (AXIAL) AND LVL (RADIAL) AND TEMPERATURE FLUCTUATIONS GQ AVERAGED OVER THE TURBULENT ZONE HAVE BEEN MADE IN A TURBULENT HEATED JET WITH A... [more]
MEASUREMENTS OF VELOCITY FLUCTUATIONS LUL (AXIAL) AND LVL (RADIAL) AND TEMPERATURE FLUCTUATIONS GQ AVERAGED OVER THE TURBULENT ZONE HAVE BEEN MADE IN A TURBULENT HEATED JET WITH A CO-FLOWING STREAM AND COMPARED WITH THE CONVENTIONALLY AVERAGED RESULTS.THE ZONE-AVERAGED MEAN TEMPERATURE AND TEMPERATURE FLUCTUATION INTENSITY APPEAR TO BE NEARLY HOMOGENEOUSLY DISTRIBUTED IN THE OUTER, INTERMITTENT REGION OF THE JET.THIS HOMOGENEITY DOES NOT APPLY TO THE LUL AND LVL FLUCTUATIONS.THE FLATNESS FACTOR OF THE TEMPERATURE WITHIN THE TURBULENT PART OF THE FLOW IS REMARKABLY CONSTANT THROUGHOUT THE INTERMITTENT REGION.ALTHOUGH THE SKEWNESS OF THE TURBULENT GQ FLUCTUATIONS IS NON-ZERO, IT IS SMALLER THAN THE SKEWNESS OF THE TURBULENT LUL AND LVL FLUCTUATIONS.THE AVERAGE GQLVL OF THE HEAT FLUX OVER THE TURBULENT ZONE INCREASES IN THE INTERMITTENT REGION WHEREAS THE ZONE-AVERAGED MOMENTUM FLUX /LUVL AND ZONE-AVERAGED HEAT FLUX /GQLUL CONTINUOUSLY DECREASE.THIS LEADS TO THE PRANDTL NUMBER OF THE TURBULENT FLUID BEING SMALLER THAN THE CONVENTIONAL PRANDTL NUMBER IN THE OUTER PART OF THE FLOW.A BUDGET FOR THE SQUARE OF THE TEMPERATURE FLUCTUATIONS WITHIN THE TURBULENT PART OF THE FLOW INDICATES A CONSTANT DISTRIBUTION OF TEMPERATURE DIS SIPATION.THE TRANSPORT OF HEAT BY THE LARGE-SCALE STRUCTURE OF THE FLOW IS BRIEFLY DISCUSSED IN THE LIGHT OF THE AVAILABLE EXPERIMENTAL INFORMATION ON OTHER TURBULENT SHEAR FLOWS.(A).
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1975 |
Antonia RA, 'Influence of velocity sensitivity on the statistics of small scale temperature fluctuations', Physics of Fluids, 18 1584-1585 (1975)
The theoretical temperature spectrum used by Wyngaard is not consistent with spectra measured in the atmospheric surface layer and leads to a significant overestimation of the eff... [more]
The theoretical temperature spectrum used by Wyngaard is not consistent with spectra measured in the atmospheric surface layer and leads to a significant overestimation of the effect of velocity sensitivity of a resistance-wire temperature sensor on the skewness of the temperature derivative. Copyright © 1975 American Institute of Physics.
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1975 |
Wood DH, Antonia RA, 'MEASUREMENTS IN A TURBULENT BOUNDARY LAYER OVER A d-TYPE SURFACE ROUGHNESS.', American Society of Mechanical Engineers (Paper), (1975)
Mean velocity and turbulence intensity measurements have been made in a fully developed turbulent boundary layer over a d-type surface roughness. This roughness is characterized b... [more]
Mean velocity and turbulence intensity measurements have been made in a fully developed turbulent boundary layer over a d-type surface roughness. This roughness is characterized by regular two-dimensional elements of square cross section placed one element width apart, with the cavity flow between elements being essentially isolated from the outer flow. The measurements show that this boundary layer closely satisfies the requirement of exact self-preservation. Distribution across the layer of Reynolds normal and shear stresses are closely similar to those found over a smooth surface except for the region immediately above the grooves.
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1975 |
Ahmad QA, Luxton RE, Antonia RA, 'BEHAVIOR OF A TWO-DIMENSIONAL WAKE IN A UNIFORMLY SHEARED TURBULENT FLOW.', American Society of Mechanical Engineers (Paper), (1975)
The behavior of a cylinder wake in a weak uniformly sheared external stream is studied. It is found that the departure of the wake from the linear velocity distribution of the ext... [more]
The behavior of a cylinder wake in a weak uniformly sheared external stream is studied. It is found that the departure of the wake from the linear velocity distribution of the external flow is approximately self preserving. There is a tendency for the wake to grow faster on the ¿high velocity¿ side (where alpha U/ alpha y has the same sign inside and outside the wake) than on the ¿low velocity¿ side (where the signs of alpha U/ alpha y are different). This result agrees with the limited evidence on the growth of boundary layers under a uniformly sheared free stream. The turbulence structures on the two sides of the wake appear to behave independently of each other.
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1975 |
Antonia RA, Beck RE, 'Turbulent boundary layers with wall injection', AIAA Journal, 13 952-954 (1975)
IN THIS NOTE, THE METHOD OF BRADSHAW, FERRIS AND ATWELL IS USED TO CALCULATE THE PERTURBED FLOW REGION DOWNSTREAM OF A DISCONTINUITY IN SURFACE INJECTION.... [more]
IN THIS NOTE, THE METHOD OF BRADSHAW, FERRIS AND ATWELL IS USED TO CALCULATE THE PERTURBED FLOW REGION DOWNSTREAM OF A DISCONTINUITY IN SURFACE INJECTION.
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1975 |
ANTONIA RA, WOOD DH, 'CALCULATION OF A TURBULENT BOUNDARY LAYER DOWNSTREAM OF A SMALL STEP CHANGE IN SURFACE ROUGHNESS.', AERONAUT. Q., 26 (1975)
MEASUREMENTS OF MEAN VELOCITY AND REYNOLDS SHEAR STRESS HAVE BEEN MADE IN A TURBULENT BOUNDARY LAYER DOWNSTREAM OF A SMALL STEP CHANGE IN SURFACE ROUGHNESS.UPSTREAM OF THE STEP TH... [more]
MEASUREMENTS OF MEAN VELOCITY AND REYNOLDS SHEAR STRESS HAVE BEEN MADE IN A TURBULENT BOUNDARY LAYER DOWNSTREAM OF A SMALL STEP CHANGE IN SURFACE ROUGHNESS.UPSTREAM OF THE STEP THE SURFACE IS SMOOTH, WHILE DOWNSTREAM IT CONSISTS OF A D-TYPE ROUGH WALL MADE UP BY A SERIES OF TWO-DIMENSIONAL ELEMENTS OF SQUARE CROSS SECTION PLACED TRANSVERSELY ACROSS THE FLOW AND SPACED ONE ELEMENT WIDTH APART IN THE DIRECTION OF THE FLOW.THE CALCULATED MEAN VELOCITY AND REYNOLDS SHEAR STRESS PROFILES OBTAINED USING THE METHOD OF BRADSHAW, FERRISS AND ATWELL ARE IN GOOD AGREEMENT WITH THE MEASUREMENTS THROUGHOUT THE RELAXATION REGION OF THE LAYER.WELL DOWNSTREAM THE CALCULATION METHOD ADEQUATELY REPRODUCES THE SELF-PRESERVING FEATURES OF A D-TYPE ROUGH WALL.(A)
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1975 |
Antonia RA, Wood DH, 'CALCULATION OF A TURBULENT BOUNDARY LAYER DOWNSTREAM OF A SMALL STEP CHANGE IN SURFACE ROUGHNESS.', Aeronaut Q, 26 202-210 (1975)
Measurements of mean velocity and Reynolds shear stress have been made in a turbulent boundary layer downstream of a small step change in surface roughness. Upstream of the step t... [more]
Measurements of mean velocity and Reynolds shear stress have been made in a turbulent boundary layer downstream of a small step change in surface roughness. Upstream of the step the surface is smooth, while downstream it consists of a d-type rough wall made up by a series of two-dimensional elements of square cross section placed transversely across the flow and spaced one element width apart in the direction of the flow. The calculated mean velocity and Reynolds shear stress profiles obtained using the method of Bradshaw, Ferriss and Atwell are in good agreement with the measurements throughout the relaxation region of the layer. Well downstream the calculation method adequately reproduces the self-preserving features of a d-type rough wall.
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1975 |
Wood DH, Antonia RA, 'Measurements in a turbulent boundary layer over a d-type surface roughness', Journal of Applied Mechanics, Transactions ASME, 42 591-597 (1975)
Mean velocity and turbulence intensity measurements have been made in a fully developed turbulent boundary layer over a d-type surface roughness. This roughness is characterised b... [more]
Mean velocity and turbulence intensity measurements have been made in a fully developed turbulent boundary layer over a d-type surface roughness. This roughness is characterised by regular two-dimensional elements of square cross section placed one element width apart, with the cavity flow between elements being essentially isolated from the outer flow. The measurements show that this boundary layer closely satisfies the requirement of exact self-preservation. Distribution across the layer of Reynolds normal and shear stresses are closely similar to those found over a smooth surface except for the region immediately above the grooves. This similarity extends to distributions of third and fourth-order moments of longitudinal and normal velocity fluctuations and also to the distribution of turbulent energy dissipation. The present results are compared with those obtained for a k-type or sand grained roughness. © 1975 by ASME.
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1975 |
AHMAD QA, ANTONIA RA, LUXTON RE, 'THE BEHAVIOUR OF A TWO-DIMENSIONAL WAKE IN A UNIFORMLY SHEARED TURBULENT FLOW', TRANS. A.S.M.E., SERIES, E, J. APPL. MECH., 42 (1975)
THE BEHAVIOUR OF A CYLINDER WAKE IN A WEAK UNIFORMLY SHEARED EXTERNAL STREAM IS STUDIED.IT IS FOUND THAT THE DEPARTURE OF THE WAKE FROM THE LINEAR VELOCITY DISTRIBUTION OF THE EXT... [more]
THE BEHAVIOUR OF A CYLINDER WAKE IN A WEAK UNIFORMLY SHEARED EXTERNAL STREAM IS STUDIED.IT IS FOUND THAT THE DEPARTURE OF THE WAKE FROM THE LINEAR VELOCITY DISTRIBUTION OF THE EXTERNAL FLOW IS APPROXIMATELY SELF PRESERVING.THERE IS A TENDENCY FOR THE WAKE TO GROW FASTER ON THE 'HIGH VELOCITY' SIDE (WHERE DELTAU/DELTAY HAS THE SAME SIGN INSIDE AND OUTSIDE THE WAKE) THAN ON THE 'LOW VELOCITY' SIDE (WHERE THE SIGNS OF DELTAU/DELTAY ARE DIFFERENT).THIS RESULT AGREES WITH THE LIMITED EVIDENCE ON THE GROWTH OF BOUNDARY LAYERS UNDER A UNIFORMLY SHEARED FREE STREAM.THE TURBULENCE STRUCTURES ON THE TWO SIDES OF THE WAKE APPEAR TO BEHAVE INDEPENDENTLY OF EACH OTHER.(A)
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1975 |
Wood DH, Antonia RA, 'Measurements in a turbulent boundary layer over a d-type surface roughness. (1975)
Mean velocity and turbulence intensity measurements have been made in a fully developed turbulent boundary layer over a d-type surface roughness. This roughness is characterised b... [more]
Mean velocity and turbulence intensity measurements have been made in a fully developed turbulent boundary layer over a d-type surface roughness. This roughness is characterised by regular two-dimensional elements of square cross section placed one element width apart, with the cavity flow between elements being essentially isolated from the outer flow. The measurments show that this boundary layer closely satisfies the requirement of exact self-preservation. Distribution across the layer of Reynolds normal and shear stresses are closely similar to those found over a smooth surface except for the region immediately above the grooves. This similarity extends to distributions of third and fourth-order moments of longitudinal and normal velocity fluctuations and also to the distribution of turbulent energy dissipation. The present results are compared with those obtained for a k-type or sand grained roughness. (A)
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1975 |
Ahmad QA, Antonia RA, Luxton RE, 'The behavior of a two-dimensional wake in a uniformly sheared turbulent flow. (1975)
The behaviour of a cylinder wake in a weak uniformly sheared external stream is studied. It is found that the departure of the wake from the linear velocity distribution of the ex... [more]
The behaviour of a cylinder wake in a weak uniformly sheared external stream is studied. It is found that the departure of the wake from the linear velocity distribution of the external flow is approximately self preserving. There is a tendency for the wake to grow faster on the high velocity side (where DELTAU/DELTAy has the same sign inside and outside the wake) than on the low velocity side (where the signs of DELTAU/DELTAy are different). This results agrees with the limited evidence on the growth of boundary layers under a uniformly sheared free stream. The turbulence structures on the two sides of the wake appear to behave independently of each other. (A)
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1975 |
Wood DH, Antonia RA, 'MEASUREMENTS IN A TURBULENT BOUNDARY LAYER OVER A d-TYPE SURFACE ROUGHNESS.', American Society of Mechanical Engineers (Paper), (1975)
Mean velocity and turbulence intensity measurements have been made in a fully developed turbulent boundary layer over a d-type surface roughness. This roughness is characterized b... [more]
Mean velocity and turbulence intensity measurements have been made in a fully developed turbulent boundary layer over a d-type surface roughness. This roughness is characterized by regular two-dimensional elements of square cross section placed one element width apart, with the cavity flow between elements being essentially isolated from the outer flow. The measurements show that this boundary layer closely satisfies the requirement of exact self-preservation. Distribution across the layer of Reynolds normal and shear stresses are closely similar to those found over a smooth surface except for the region immediately above the grooves.
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1975 |
Ahmad QA, Luxton RE, Antonia RA, 'BEHAVIOR OF A TWO-DIMENSIONAL WAKE IN A UNIFORMLY SHEARED TURBULENT FLOW.', American Society of Mechanical Engineers (Paper), (1975)
The behavior of a cylinder wake in a weak uniformly sheared external stream is studied. It is found that the departure of the wake from the linear velocity distribution of the ext... [more]
The behavior of a cylinder wake in a weak uniformly sheared external stream is studied. It is found that the departure of the wake from the linear velocity distribution of the external flow is approximately self preserving. There is a tendency for the wake to grow faster on the ¿high velocity¿ side (where alpha U/ alpha y has the same sign inside and outside the wake) than on the ¿low velocity¿ side (where the signs of alpha U/ alpha y are different). This result agrees with the limited evidence on the growth of boundary layers under a uniformly sheared free stream. The turbulence structures on the two sides of the wake appear to behave independently of each other.
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1975 |
Antonia RA, Luxton RE, 'Characteristics of turbulence within an internal boundary layer', Advances in Geophysics, 18 263-285 (1975)
This chapter discusses the calculations of higher order moments, propagation velocities, and spectra of fluctuations in an internal layer, which forms downstream from a change of ... [more]
This chapter discusses the calculations of higher order moments, propagation velocities, and spectra of fluctuations in an internal layer, which forms downstream from a change of surface roughness. The skewness and flatness factors near the edge of the smooth to rough internal layer suggest an intermittency of the interface associated with switching between two different turbulence fields. Although the two turbulence fields seem to have separate identities, which could be separated even where they interact at the interface, some large-scale stirring of the internal layer by the external layer may be expected. Temperature tagging of one of the layers by low intensity surface heating allows details of the switching to be determined as well as some statistical details of each of the turbulence fields. © 1974, Academic Press, Inc.
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1974 |
ANTONIA RH, LUXTON RE, 'CHARACTERISTICS OF TURBULENCE WITHIN AN INTERNAL BOUNDARY LAYER.', ADVANCES IN GEOPHYSIS: PROCS. SYMP. ON TURBULENT DIFFUSION IN ENVIRON. POLLUTION, HELD AT CHARLOTTESVILLE, VIRGINIA, APRIL 8-, 18 A 263-285 (1974)
THIS PAPER PRESENTS CALCULATIONS OF HIGHER ORDER MOMENTS, PROPAGATION VELOCITIES, AND SPECTRA OF FLUCTUATIONS IN AN INTERNAL LAYER WHICH FORMS DOWNSTREAM FROM A CHANGE OF SURFACE ... [more]
THIS PAPER PRESENTS CALCULATIONS OF HIGHER ORDER MOMENTS, PROPAGATION VELOCITIES, AND SPECTRA OF FLUCTUATIONS IN AN INTERNAL LAYER WHICH FORMS DOWNSTREAM FROM A CHANGE OF SURFACE ROUGHNESS.THE MAIN FEATURE OF THESE CALCULATIONS OF THE TURBULENCE STRUCTURE IS THAT THEY LEAD TO PHYSICALLY PENETRATING CONCLUSIONS WHICH ARE FULLY CONSISTENT WITH FORMER CONCLUSIONS BASED ON MUCH LESS SOPHISTICATED DATA ANALYSIS.(FROM PAPER)
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1974 |
ANTONIA RA, BILGER RW, 'THE PREDICTION OF THE AXISYMMETRIC TURBULENT JET ISSUING INTO A CO-FLOWING STREAM.', AERONAUT. QUART., 25 (1974)
THREE ANALYSES ARE PRESENTED FOR PREDICTING THE DEVELOPMENT OF AN AXISYMMETRIC TURBULENT JET ISSUING INTO A CO-FLOWING EXTERNAL AIR STREAM.THE FIRST ANALYSIS IS ANALOGOUS TO A MET... [more]
THREE ANALYSES ARE PRESENTED FOR PREDICTING THE DEVELOPMENT OF AN AXISYMMETRIC TURBULENT JET ISSUING INTO A CO-FLOWING EXTERNAL AIR STREAM.THE FIRST ANALYSIS IS ANALOGOUS TO A METHOD USED BY PATEL TO PREDICT THE GROWTH OF A TWO-DIMENSIONAL JET IN AN EXTERNAL AIR STREAM.THE METHOD IS FOUND TO BE INADEQUATE WHEN THE EXCESS VELOCITY ON THE AXIS OF THE JET BECOMES SMALL COMPARED WITH THE EXTERNAL STREAM VELOCITY.THE SECOND ANALYSIS ASSUMES THAT THE TURBULENCE STRUCTURE IS SIMILAR AT DIFFERENT STREAMWISE STATIONS BUT IT BREAKS DOWN WHEN THE ADVECTION OF TURBULENT ENERGY BECOMES COMPARABLE WITH THE TURBULENT ENERGY PRODUCTION.IN THE THIRD APPROACH, A TWO-PARAMETER MODEL OF TURBULENCE DEVELOPED BY RODI AND SPALDING, WHICH USES TWO DIFFERENTIAL EQUATIONS FOR THE TURBULENT ENERGY AND THE LENGTH SCALE OF THE TURBULENCE RESPECTIVELY, IS FOUND TO PREDICT CLOSELY THE EXPERIMENTAL RESULTS OF ANTONIA AND BILGER FOR A RATIO OF JET TO EXTERNAL STREAM VELOCITY OF 3.0.THE SUCCESS OF THIS LAST METHOD EMPHASISES THE NON-SIMILAR CHARACTER OF TURBULENCE.(A).
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1974 |
Antonia RA, Bilger RW, 'PREDICTION OF THE AXISYMMETRIC TURBULENT JET ISSUING INTO A CO-FLOWING STREAM.', Aeronaut Q, 25 69-80 (1974)
Three analysis are presented for predicting the development of an axisymmetric turbulent jet issuing into a co-flowing external air stream. The first analysis is analogous to a me... [more]
Three analysis are presented for predicting the development of an axisymmetric turbulent jet issuing into a co-flowing external air stream. The first analysis is analogous to a method used by Patel to predict the growth of a two-dimensional jet in an external air stream. The method is found to be inadequate when the excess velocity on the axis of the jet becomes small compared with the external stream velocity. The second analysis assumes that the turbulent structure is similar at different streamwise stations but it breaks down when the advection of turbulent energy becomes comparable with the turbulent energy production. In the third approach, a two-parameter model of turbulence developed by Rodi and Spalding, which uses two differential equations for the turbulent energy and the length scale of the turbulence respectively, is found to predict closely the experimental results of Antonia and Bilger for a ratio of jet to external stream velocity of 3. 0. The success of this last method emphasises the nonsimilar character of turbulence.
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1974 |
Antonia RA, 'DISTRIBUTION OF TEMPERATURE IN THE INTERMITTENT REGION OF A TURBULENT SHEAR FLOW. 95-98 (1974)
Use is made of the conditional sampling technique to investigate the structure of temperature fluctuations in the intermittent region of a turbulent round jet with a co-flowing ir... [more]
Use is made of the conditional sampling technique to investigate the structure of temperature fluctuations in the intermittent region of a turbulent round jet with a co-flowing irrotational air stream. The ensemble averages of the temperature fluctuations within the turbulent part only of the flow are presented and discussed with reference to observed temperature signals in turbulent boundary layers and other shear flows.
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1974 |
Antonia RA, 'STRUCTURE OF VELOCITY AND TEMPERATURE FLUCTUATIONS IN A TURBULENT JET. 325-331 (1974)
The intermittency characteristics of a turbulent axisymmetric heated jet with a co-flowing stream have been investigated. The intermittency factor and the frequency of the turbule... [more]
The intermittency characteristics of a turbulent axisymmetric heated jet with a co-flowing stream have been investigated. The intermittency factor and the frequency of the turbulent/irrotational interface are obtained for three values of the ratio of free stream to jet velocity and the results are compared with those for the nonisothermal jet into still air and the axisymmetric wake. The intermittent temperature signal is used to obtain conditional averages of the axial velocity fluctuation and the axial turbulent heat flux. The results emphasize the importance of the large scale structure in this flow.
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1974 |
Antonia RA, Atkinson JD, 'Use of a pseudo-turbulent signal to calibrate an intermittency measuring circuit', Journal of Fluid Mechanics, 64 679-699 (1974)
Measurements of the intermittency factor ¿ and in particular the crossing frequency f¿ of the turbulent/non-turbulent interface in the outer regions of various turbulent shear flo... [more]
Measurements of the intermittency factor ¿ and in particular the crossing frequency f¿ of the turbulent/non-turbulent interface in the outer regions of various turbulent shear flows depend strongly on the settings of the intermittency meter used. Two methods of calibrating an intermittency meter of conventional design are described. In the first, turbulent and non-turbulent signals are simulated and switched at random times using an analog computer. Particular attention is given to the spectra of the switching and turbulent signals but the non-turbulent signal is assumed to have the same spectrum as the turbulent signal. In the second method, the same switching process is applied to two real signals, obtained in the fully turbulent and irretational flow regions associated with a turbulent jet with a co-flowing external air stream. A rather simple calibration procedure derived using the results of both methods is applied to the measurements of ¿ and f¿ in the same jet. It is suggested that the simulation process adopted here could be useful in inferring properties of intermittent turbulent flows. © 1974, Cambridge University Press. All rights reserved.
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1974 |
Antonia RA, Van Atta CW, 'Prediction of high order moments of turbulent temperature derivatives for large Reynolds numbers', Physics of Fluids, 17 1776-1777 (1974)
An analysis based on a consideration of the structure functions of passive turbulent temperature fluctuations explains the experimental Reynolds number dependence of the flatness ... [more]
An analysis based on a consideration of the structure functions of passive turbulent temperature fluctuations explains the experimental Reynolds number dependence of the flatness factor of temperature derivatives reasonably well. Copyright © 1974 American Institute of Physics.
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1973 |
Antonia RA, Atkinson JD, 'High-order moments of Reynolds shear stress fluctuations in a turbulent boundary layer', Journal of Fluid Mechanics, 58 581-593 (1973)
The cumulant-discard approach is used to predict the third and fourth-order moments and the probability density of turbulent Reynolds shear stress fluctuations uv, the streamwise ... [more]
The cumulant-discard approach is used to predict the third and fourth-order moments and the probability density of turbulent Reynolds shear stress fluctuations uv, the streamwise and normal velocity fluctuations being represented by u and v respectively. Measurements of these quantities in a turbulent boundary layer are presented, with the required statistics of uv obtained by the use of a high-speed digital data-acquisition system. Including correlations between u and v up to the fourth order, the cumulant-discard predictions are in close agreement with the measurements in the inner region of the layer but only qualitatively follow the experimental results in the outer intermittent region. In this latter region, predictions for the third- and fourth-order monents of uv are also obtained by assuming that the properties of both turbulent and irrotational fluctuations are Gaussian and by using some of the available conditional averages of u, v and uv. (A)
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1973 |
ANTONIA RA, BILGER RW, 'AN EXPERIMENTAL INVESTIGATION OF AN AXISYMMETRIC JET IN A CO-FLOWING AIR STREAM.', Journal of Fluid Mechanics, 61 (1973)
AN EXPERIMENTAL INVESTIGATION OF THE FLOW DEVELOPMENT OF AN AXISYMMETRIC JET EXHAUSTING INTO A MOVING AIR STREAM IS MADE FOR TWO VALUES OF THE RATIO OF JET VELOCITY TO EXTERNAL AI... [more]
AN EXPERIMENTAL INVESTIGATION OF THE FLOW DEVELOPMENT OF AN AXISYMMETRIC JET EXHAUSTING INTO A MOVING AIR STREAM IS MADE FOR TWO VALUES OF THE RATIO OF JET VELOCITY TO EXTERNAL AIR VELOCITY.THE U-COMPONENT TURBULENCE INTENSITY AND REYNOLDS SHEAR STRESS MEASUREMENTS TOGETHER WITH THE DISSIPATION LENGTH SCALES INFERRED FROM MEASURED U-COMPONENT SPECTRA SUGGEST THAT THE TURBULENCE SIMILARITY ASSUMPTIONS ARE INCORRECT FOR THE PRESENT FLOW SITUATION.A DISCUSSION OF THE TURBULENCE STRUCTURE OF THE FLOW INDICATES THAT SELF-PRESERVATION DOES NOT APPLY FOR THIS SITUATION AND THAT THE FLOW FAR DOWNSTREAM DEPENDS STRONGLY ON THE COMPLETE PAST HISTORY.(A)
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1973 |
Antonia RA, Atkinson JD, 'High-order moments of Reynolds shear stress fluctuations in a turbulent boundary layer', Journal of Fluid Mechanics, 58 581-593 (1973)
The cumulant-discard approach is used to predict the third- and fourth-order moments and the probability density of turbulent Reynolds shear stress fluctuations uv, the streamwise... [more]
The cumulant-discard approach is used to predict the third- and fourth-order moments and the probability density of turbulent Reynolds shear stress fluctuations uv, the streamwise and normal velocity fluctuations being represented by u and v respectively. Measurements of these quantities in a turbulent boundary layer are presented, with the required statistics of uv obtained by the use of a high-speed digital data-acquisition system. Including correlations between u and u up to the fourth order, the cumulant-discard predictions are in close agreement with the measurements in the inner region of the layer but only qualitatively follow the experimental results in the outer intermittent region. In this latter region, predictions for the third- and fourth-order moments of uv are also obtained by assuming that the properties of both turbulent and irrotational fluctuations are Gaussian and by using some of the available conditional averages of u, v and uv. © 1973, Cambridge University Press. All rights reserved.
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1973 |
Antonia RA, Bilger RW, 'An experimental investigation of an axisymmetric jet in a co-flowing air stream', Journal of Fluid Mechanics, 61 805-822 (1973)
An experimental investigation of the flow development of an axisymmetric jet exhausting into a moving air stream is made for two values of the ratio of jet velocity to external ai... [more]
An experimental investigation of the flow development of an axisymmetric jet exhausting into a moving air stream is made for two values of the ratio of jet velocity to external air velocity. The u-component turbulence intensity and Reynolds shear stress measurements together with the dissipation length scales inferred from measured u-component spectra suggest that the turbulence similarity assumptions are incorrect for the present flow situation. A discussion of the turbulence structure of the flow indicates that self-preservation does not apply for this situation and that the flow far downstream depends strongly on the complete past history. © 1973, Cambridge University Press. All rights reserved.
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1973 |
Antonia RA, 'Some small scale properties of boundary layer turbulence', Physics of Fluids, 16 1198-1206 (1973)
The distributions across a smooth wall layer of the skewness and flatness factor of the first-order time derivatives of u and v, the longitudinal and normal velocity fluctuations,... [more]
The distributions across a smooth wall layer of the skewness and flatness factor of the first-order time derivatives of u and v, the longitudinal and normal velocity fluctuations, respectively, and of uv, the Reynolds shear stress fluctuations, are compared with the corresponding distributions in a boundary layer over a rough wall Both the smooth and rough wall boundary layers are nearly self-preserving under zero pressure gradient conditions. Although the probability density of the square of ¿u/¿t, the time derivative of u, is reasonably represented by the log-normal distribution, the skewness and flatness factor of ¿u/¿t in the inner region of the layers are found to remain approximately constant for a turbulence Reynolds number R ¿ range 150-450.
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1973 |
Antonia RA, Atkinson JD, Luxton RE, 'Comments on "Statistical characteristics of Reynolds stress in a turbulent boundary layer"', Physics of Fluids, 16 956 (1973)
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1972 |
Antonia RA, 'Conditionally sampled measurements near the outer edge of a turbulent boundary layer', Journal of Fluid Mechanics, 56 1-18 (1972)
The conditional sampling technique is used to measure ensemble averages of the longitudinal and normal velocity fluctuations u and v respectively and of the Reynolds shear stress ... [more]
The conditional sampling technique is used to measure ensemble averages of the longitudinal and normal velocity fluctuations u and v respectively and of the Reynolds shear stress fluctuations uv both within the turbulent and irrotational regions near the outer edge of a turbulent boundary layer. The measurements are made in both a smooth- and a rough-wall boundary layer under zero-pressure-gradient conditions. The smooth- and rough-wall results are qualitatively similar but the magnitude of the rough-wall averages is higher than that of the smooth- wall averages, corresponding with the higher value of wall shear stress on the rough surface. The maximum shear stress value encountered within a burst represents a significant proportion of the wall shear stress. The statistical properties of the turbulence within the burst are close but not quite identical to the nearly Gaussian properties of the inner region of the boundary layer. During an attempt to distinguish between bursts of different ages or strengths at the time of measurement, it was found that bursts of relatively short duration travel at much the same longitudinal velocity as the local mean U and contribute little to the local shear stress. The longer and less frequent bursts have a mean velocity smaller than U and a maximum shear stress comparable to the shear stress at the wall. © 1972, Cambridge University Press. All rights reserved.
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1972 |
Antonia RA, Luxton RE, 'The response of a turbulent boundary layer to a step change in surface roughness. Part 2. Rough-to-smooth', Journal of Fluid Mechanics, 53 737-757 (1972)
An experimental study of the structure of the internal layer which grows downstream from a rough-to-smooth surface change shows it to be essentially different from that studied by... [more]
An experimental study of the structure of the internal layer which grows downstream from a rough-to-smooth surface change shows it to be essentially different from that studied by Antonia & Luxton (19716) for the case of a smooth-to-rough perturbation. The rate of growth of the internal layer is less than that for the smooth-to-rough step and it appears that the more intense initial rough-wall flow dictates the rate of diffusion of the disturbance for a considerable distance. Inside the internal layer the mixing length I is increased relative to the equilibrium distribution I = Ky. A turbulent energy budget shows that the advection is comparable with the production or dissipation, whilst there seems to be some diffusion of energy into the internal-layer region close to the wall. The boundary layer, as a whole, recovers much more slowly following a rough-to-smooth change than following a smooth-to-rough change, and at the last measuring station (16 boundary-layer thicknesses from the start of the smooth surface) the distributions of mean velocity and Reynolds shear stress are far from self-preserving. © 1972, Cambridge University Press. All rights reserved.
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1972 |
Antonia RA, 'Measurements of Reynolds shear stress fluctuations in a turbulent boundary layer', Physics of Fluids, 15 1669-1670 (1972)
Measurements in both smooth and rough wall boundary layers show that the rms of the Reynolds shear stress fluctuation is approximately twice the wall shear stress value in the reg... [more]
Measurements in both smooth and rough wall boundary layers show that the rms of the Reynolds shear stress fluctuation is approximately twice the wall shear stress value in the region close to the wall and equal to about three times the local shear stress throughout most of the smooth wall layer.
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1971 |
Antonia RA, Luxton RE, 'The response of a turbulent boundary layer to a step change in surface roughness Part 1. Smooth to rough', Journal of Fluid Mechanics, 48 721-761 (1971)
The structure and growth of the internal boundary layer which forms downstream of a sudden change from a smooth to a rough surface under zero pressure gradient conditions has been... [more]
The structure and growth of the internal boundary layer which forms downstream of a sudden change from a smooth to a rough surface under zero pressure gradient conditions has been studied experimentally. To keep pressure disturbances due to the roughness change small, the level of the rough surface was depressed, so that the crest of the roughness was aligned with the level of the smooth surface. It has been found that, in the region near the change, the structure of the internal layer is largely independent of that in the almost undisturbed outer layer, whilst both the zero time delay and the moving axis integral length scales in the internal layer are significantly reduced below those on the smooth wall. The growth-rate of the internal layer is similar to that of the zero pressure gradient boundary layer, whilst the level of turbulence inside the internal layer is high because of the large turbulent energy production near the rough wall. From the mixing length results, and an analysis of the turbulent energy equation, it is deduced that the internal layer flow near the wall is not in energy equilibrium, and hence the concept of inner layer similarity breaks down. From an initially self-preserving state on the smooth wall, the turbulent boundary layer approaches a second self-preserving state on the rough wall well downstream of the roughness step. © 1971, Cambridge University Press. All rights reserved.
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1971 |
Antonia RA, Luxton RE, 'Energy balance in a turbulent boundary layer on a rough wall', Physics of Fluids, 14 1027-1029 (1971)
Measurements of the mean flow and turbulence fields over a two-dimensional roughness reveal a shear stress distribution which is very different from that on a smooth wall. The usu... [more]
Measurements of the mean flow and turbulence fields over a two-dimensional roughness reveal a shear stress distribution which is very different from that on a smooth wall. The usual mean flow energy equation fails to close indicating other terms may be important.
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1971 |
Antonia RA, Luxton RE, 'The response of a turbulent boundary layer to an upstanding step change in surface roughness', Journal of Fluids Engineering, Transactions of the ASME, 93 22-32 (1971)
Measurements of the flow field downstream of an upstanding step change in surface roughness are presented. The roughness has the form of two-dimensional square section ribs placed... [more]
Measurements of the flow field downstream of an upstanding step change in surface roughness are presented. The roughness has the form of two-dimensional square section ribs placed transversely across the floor of the wind tunnel with the first element upstanding from the surface. The surface upstream of the roughness is smooth and is of sufficient length to allow a fully developed smooth wall turbulent boundary layer to be established. The roughness height is approximately 6 percent of the boundary layer thickness on the smooth wall just upstream of the first roughness element. It is observed that downstream of the start of the roughness, the mean velocity profiles inside the internal layer (i.e., that part of the boundary layer which has been affected by the new inner boundary condition) exhibit a linear trend when plotted in the form U versus y1/2. Remarkably, it is also found that a linear trend is exhibited by points in the ¿undisturbed¿ boundary layer outside the internal layer when plotted in the above manner, and that the slope in the undisturbed layer differs from that in the internal layer. The undisturbed layer slope appears to depend on conditions upstream of the roughness. It is suggested that the point of inter section of the two straight lines (the ¿knee¿ point) on the U versus y1/2 plot may be used to define the edge of the internal layer. Turbulence intensity distributions and spectra are presented from which it is deduced that the internal and external layer structures are largely independent and that streamwise length scales in the internal layer over the rough wall are reduced significantly below those at the equivalent station over a smooth wall. © 1971 by ASME.
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