Dr Farzin Ghanadi
Research Associate
School of Engineering
 Email:farzin.ghanadi@newcastle.edu.au
 Phone:(02) 4985 4938
Career Summary
Biography
Qualifications
 Doctor of Philosophy, University of Adelaide
Keywords
 Experimental and Computational Fluid Dynamic
 Fluid Mechanics
 Mechanical Engineering
 Turbulence
Languages
 English (Fluent)
Professional Experience
UON Appointment
Title  Organisation / Department 

Academic appointment
Dates  Title  Organisation / Department 

10/2/2015  26/5/2019  Research Associate  University of Adelaide Mechanical Engineering 
Publications
For publications that are currently unpublished or inpress, details are shown in italics.
Journal article (22 outputs)
Year  Citation  Altmetrics  Link  

2021 
Jafari A, Emes M, Cazzolato B, Ghanadi F, Arjomandi M, 'Wire mesh fences for manipulation of turbulence energy spectrum', Experiments in Fluids, 62 (2021) © 2021, The Author(s), under exclusive licence to SpringerVerlag GmbH, DE part of Springer Nature. Manipulation of turbulence within an atmospheric boundary layer flow by applica... [more] © 2021, The Author(s), under exclusive licence to SpringerVerlag GmbH, DE part of Springer Nature. Manipulation of turbulence within an atmospheric boundary layer flow by application of woven wire mesh fences is investigated. Turbulence properties behind fences of different porosities and mesh opening widths were determined from velocity measurements in a wind tunnel. It is found that with the application of a fence with a porosity of 0.46, the streamwise turbulence intensity can be reduced from the inflow level of 12.5%¿8.8% and the integral length scale can be reduced from 380 to 270¿mm. The results show that behind the mesh fences turbulence kinetic energy decays as a power law function of the downstream distance for all wire mesh fences tested in the wind tunnel. The decay rate of turbulence kinetic energy is faster, and a larger reduction in the integral length scale is achieved for fences with porosities between 0.46 and 0.64 compared to higher porosities of between 0.73 and 0.75. Porosity of the woven wire meshes is found to be the key parameter which influences their turbulence reduction performance. In the end, application of the wire mesh fences for reduction of wind loads on solar panels and heliostats is discussed. Evaluation of wind loads based on the reduction of turbulence intensity and integral length scale shows that up to 48% and 53% reduction in peak drag and lift forces on a heliostat, respectively, can be achieved with application of mesh fences. Graphic abstract: [Figure not available: see fulltext.]


2020 
Ghanadi F, Torres JF, Arjomandi M, Pye J, 'Flow structure and convective heat transfer in a bladed structure under wind conditions', International Journal of Heat and Fluid Flow, 85 (2020) [C1]


2020 
Jafari A, Emes M, Cazzolato B, Ghanadi F, Arjomandi M, 'Turbulence characteristics in the wake of a heliostat in an atmospheric boundary layer flow', Physics of Fluids, 32 (2020) [C1]


2019 
Emes MJ, Arjomandi M, Kelso RM, Ghanadi F, 'Turbulence length scales in a lowroughness nearneutral atmospheric surface layer', JOURNAL OF TURBULENCE, 20 545562 (2019) [C1]


2017 
Lee KL, Jafarian M, Ghanadi F, Arjomandi M, Nathan GJ, 'An investigation into the effect of aspect ratio on the heat loss from a solar cavity receiver', SOLAR ENERGY, 149 2031 (2017)


2017 
Emes MJ, Arjomandi M, Ghanadi F, Kelso RM, 'Effect of turbulence characteristics in the atmospheric surface layer on the peak wind loads on heliostats in stow position', SOLAR ENERGY, 157 284297 (2017)


2017 
Silvestri A, Ghanadi F, Arjomandi M, Cazzolato B, Zander A, 'Attenuation of sweep events in a turbulent boundary layer using microcavities', EXPERIMENTS IN FLUIDS, 58 (2017)


2017 
Silvestri A, Ghanadi F, Arjomandi M, Chin R, Cazzolato B, Zander A, 'Attenuation of turbulence by the passive control of sweep events in a turbulent boundary layer using microcavities', PHYSICS OF FLUIDS, 29 (2017)


2015 
Ghanadi F, Arjomandi M, Cazzolato BS, Zander AC, 'Analysis of the turbulent boundary layer in the vicinity of a selfexcited cylindrical Helmholtz resonator', JOURNAL OF TURBULENCE, 16 705728 (2015)


2014 
Ghanadi F, Arjomandi M, Cazzolato B, Zander A, 'Understanding of the flow behaviour on a Helmholtz resonator excited by grazing flow', INTERNATIONAL JOURNAL OF COMPUTATIONAL FLUID DYNAMICS, 28 219231 (2014)


2014 
Ghanadi F, Arjomandi M, Cazzolato B, Zander A, 'Interaction of a flowexcited Helmholtz resonator with a grazing turbulent boundary layer', EXPERIMENTAL THERMAL AND FLUID SCIENCE, 58 8092 (2014)


2013 
Ghanadi F, Arjomandi M, Zander AC, Cazzolato BS, 'Numerical simulation of grazing flow over a selfexcited Helmholtz resonator', Engineering Letters, 21 137142 (2013) Selfsustained oscillations of the grazing flow along the orifice of a Helmholtz resonator were considered numerically. These fluctuations are driven by hydrodynamic instabilities... [more] Selfsustained oscillations of the grazing flow along the orifice of a Helmholtz resonator were considered numerically. These fluctuations are driven by hydrodynamic instabilities inside the shear layer and the resonant acoustical field. Quantitative prediction of this process requires accurate calculations of grazing flow characteristics over the three dimensional resonator. In this paper flow excitation phenomenon assumed to be associated with external pressure fluctuations within the turbulent boundary layer of grazing flow and acoustic response of the cavity. To this end a Large Eddy Simulation (LES) of the three dimensional shear flow over the orifice carried out at a low Mach number to allow predictions of the amplitude and frequency of the pressure and velocity fluctuations. For validation propose, for pressure fluctuations inside the cavity, a good quantitative agreement with published data was obtained. Therefore the simulations provide an ability to predict the resonating frequency, pressure and velocity field for different inlet conditions.


Show 19 more journal articles 
Conference (26 outputs)
Year  Citation  Altmetrics  Link  

2020 
Severino G, Silvestri A, Ghanadi F, Cazzolato B, Arjomandi M, 'Comparison of turbulent boundary layer energy spectrum analyses for multiple tripping techniques', AIAA Scitech 2020 Forum, Orlando, Florida (2020) [E1]


2019 
Emes MJ, Jafari A, Ghanadi F, Arjomandi M, 'A Method for the Calculation of the Design Wind Loads on Heliostats', SOLARPACES 2018: INTERNATIONAL CONFERENCE ON CONCENTRATING SOLAR POWER AND CHEMICAL ENERGY SYSTEMS, Casablanca, MOROCCO (2019)


2019 
Pye J, Abbasi E, Arjomandi M, Coventry J, Ghanadi F, Hughes G, et al., 'Towards Testing of a SecondGeneration Bladed Receiver', SOLARPACES 2018: INTERNATIONAL CONFERENCE ON CONCENTRATING SOLAR POWER AND CHEMICAL ENERGY SYSTEMS, Casablanca, MOROCCO (2019)


2018 
Steer J, Li SW, Morcom N, Jucius S, Ghanadi F, Arjomandi M, 'Pedestrianlevel wind conditions around buildings for wind comfort assessment', Proceedings of the 21st Australasian Fluid Mechanics Conference, AFMC 2018 (2018) © 2018 Australasian Fluid Mechanics Society. All rights reserved. The practice of investigating the pedestrian level wind environment, so called wind engineering, is now ubiquitou... [more] © 2018 Australasian Fluid Mechanics Society. All rights reserved. The practice of investigating the pedestrian level wind environment, so called wind engineering, is now ubiquitous. Many city case studies exist in literature but few systematic studies of common urban architectural features exist. Among these common features is the simple channel which is common in large cities and has been well documented in literature as leading to significant wind speed increases. This study investigates the effects of adding a blockage at the channel inlet on observed velocities in the channel centerline on 1:100 scale with a view to applying the results to full scale. Time averaged velocity profiles were used to investigate the effect of blockage size and channel width on wind speed amplification. It was found that counterintuitively, the size of the blockage at the inlet is not proportional to the size of the peak velocity reduction in the channel. The largest blockage created a minimum flow speed reduction (K = 0.98) for a channel width of 200mm. It was outperformed by the smallest blockage for a channel width of 300mm where a greater speed reduction was observed (K = 1.04). It was found that for buildings nearing the interaction flow regime the addition of a blockage has negligible effect on speed. 

2018 
Jafari A, Ghanadi F, Emes MJ, Arjomandi M, Cazzolato BS, 'Effect of freestream turbulence on the drag force on a flat plate', Proceedings of the 21st Australasian Fluid Mechanics Conference, AFMC 2018 (2018) © 2018 Australasian Fluid Mechanics Society. All rights reserved. The effect of intensity and length scale of turbulence on the mean and fluctuating drag forces on a flat plate no... [more] © 2018 Australasian Fluid Mechanics Society. All rights reserved. The effect of intensity and length scale of turbulence on the mean and fluctuating drag forces on a flat plate normal to a boundary layer flow is investigated. Experiments were conducted at the University of Adelaide large wind tunnel to measure the drag force on flat plates of different areas. Two boundary layers of different depths were generated by spires and roughness elements to achieve a range of longitudinal turbulence intensities between 12% and 26% and integral length scales between 0.4 m and 1.22 m. The rootmeansquare of the fluctuating drag coefficient was well correlated with a turbulence parameter defined as a function of turbulence intensity (Iu) and integral length scale (Lxu). The results showed that both the fluctuating and the peak drag coefficients increased logarithmically with increasing the turbulence parameter such that increasing the turbulence parameter from 0.11 to 0.47 increased the peak drag coefficient from 1.73 to 3.


2018 
Torres JF, Ghanadi F, Arjomandi M, Pye J, 'Vortex dynamics within a bladed structure in mixed convection', Proceedings of the 21st Australasian Fluid Mechanics Conference, AFMC 2018 (2018) © 2018 Australasian Fluid Mechanics Society. All rights reserved. Mixed convection is generally the dominant form of convective heat transfer in large heated structures at mid to... [more] © 2018 Australasian Fluid Mechanics Society. All rights reserved. Mixed convection is generally the dominant form of convective heat transfer in large heated structures at mid to low temperatures or in small heated structures at hightemperatures, as in solar thermal receivers for concentrating solar power, which is the motivation for the present study. Novel bladed receiver designs have been proposed for reducing thermal emission and improving light trapping. However, convective heat losses from these bladed structures (extended surfaces) may increase compared to nonbladed geometries, which is not desirable as thermal efficiencies may drop. In this study, experimentvalidated simulations were used to quantify heat transfer coefficients for a varying blade length and number of blades. The back wall pitch angle ¿ was fixed to 30° and 60° with headwind of 6 m/s and wall temperature of 300°C; the turbulence intensity at the inlet was 1%. A numerical simulation based on the threedimensional SST k¿¿ turbulence model was performed in OpenFOAM to determine the heat transfer rates and flow behaviour. For a fixed back wall dimension (300 × 300 mm), simulations were conducted for varying the blade number (Nb) while fixing the blade length to spacing ratio to RBS = 1, and varying RBS for Nb = 5. Some interesting vortex dynamics were observed in each case. First, for variable aspect ratio, a transition from a single roll to a tworoll flow between the blade spacing was confirmed at RBS ¿ 1.5 for both pitch angles of ¿ = 30° and 60°. Second, for variable blade number, a transition to a liddrivenlike convection was observed beyond the blade number of Nb = 7, which decreased the heat transfer rate. A larger number of vortices between the blades was responsible for the drop in convective heat transfer coefficient, reaching values even less than the flat case for Nb > 23.


2018 
Jafari A, Ghanadi F, Emes MJ, Arjomandi M, Cazzolato BS, 'Effect of freestream turbulence on the drag force on a flat plate', Proceedings of the 21st Australasian Fluid Mechanics Conference, AFMC 2018 (2018) © 2018 Australasian Fluid Mechanics Society. All rights reserved. The effect of intensity and length scale of turbulence on the mean and fluctuating drag forces on a flat plate no... [more] © 2018 Australasian Fluid Mechanics Society. All rights reserved. The effect of intensity and length scale of turbulence on the mean and fluctuating drag forces on a flat plate normal to a boundary layer flow is investigated. Experiments were conducted at the University of Adelaide large wind tunnel to measure the drag force on flat plates of different areas. Two boundary layers of different depths were generated by spires and roughness elements to achieve a range of longitudinal turbulence intensities between 12% and 26% and integral length scales between 0.4 m and 1.22 m. The rootmeansquare of the fluctuating drag coefficient was well correlated with a turbulence parameter defined as a function of turbulence intensity (Iu) and integral length scale (Lxu). The results showed that both the fluctuating and the peak drag coefficients increased logarithmically with increasing the turbulence parameter such that increasing the turbulence parameter from 0.11 to 0.47 increased the peak drag coefficient from 1.73 to 3.


2018 
Torres JF, Ghanadi F, Arjomandi M, Pye J, 'Vortex dynamics within a bladed structure in mixed convection', Proceedings of the 21st Australasian Fluid Mechanics Conference, AFMC 2018 (2018) © 2018 Australasian Fluid Mechanics Society. All rights reserved. Mixed convection is generally the dominant form of convective heat transfer in large heated structures at mid to... [more] © 2018 Australasian Fluid Mechanics Society. All rights reserved. Mixed convection is generally the dominant form of convective heat transfer in large heated structures at mid to low temperatures or in small heated structures at hightemperatures, as in solar thermal receivers for concentrating solar power, which is the motivation for the present study. Novel bladed receiver designs have been proposed for reducing thermal emission and improving light trapping. However, convective heat losses from these bladed structures (extended surfaces) may increase compared to nonbladed geometries, which is not desirable as thermal efficiencies may drop. In this study, experimentvalidated simulations were used to quantify heat transfer coefficients for a varying blade length and number of blades. The back wall pitch angle ¿ was fixed to 30° and 60° with headwind of 6 m/s and wall temperature of 300°C; the turbulence intensity at the inlet was 1%. A numerical simulation based on the threedimensional SST k¿¿ turbulence model was performed in OpenFOAM to determine the heat transfer rates and flow behaviour. For a fixed back wall dimension (300 × 300 mm), simulations were conducted for varying the blade number (Nb) while fixing the blade length to spacing ratio to RBS = 1, and varying RBS for Nb = 5. Some interesting vortex dynamics were observed in each case. First, for variable aspect ratio, a transition from a single roll to a tworoll flow between the blade spacing was confirmed at RBS ¿ 1.5 for both pitch angles of ¿ = 30° and 60°. Second, for variable blade number, a transition to a liddrivenlike convection was observed beyond the blade number of Nb = 7, which decreased the heat transfer rate. A larger number of vortices between the blades was responsible for the drop in convective heat transfer coefficient, reaching values even less than the flat case for Nb > 23.


2018 
Steer J, Li SW, Morcom N, Jucius S, Ghanadi F, Arjomandi M, 'Pedestrianlevel wind conditions around buildings for wind comfort assessment', Proceedings of the 21st Australasian Fluid Mechanics Conference, AFMC 2018 (2018) © 2018 Australasian Fluid Mechanics Society. All rights reserved. The practice of investigating the pedestrian level wind environment, so called wind engineering, is now ubiquitou... [more] © 2018 Australasian Fluid Mechanics Society. All rights reserved. The practice of investigating the pedestrian level wind environment, so called wind engineering, is now ubiquitous. Many city case studies exist in literature but few systematic studies of common urban architectural features exist. Among these common features is the simple channel which is common in large cities and has been well documented in literature as leading to significant wind speed increases. This study investigates the effects of adding a blockage at the channel inlet on observed velocities in the channel centerline on 1:100 scale with a view to applying the results to full scale. Time averaged velocity profiles were used to investigate the effect of blockage size and channel width on wind speed amplification. It was found that counterintuitively, the size of the blockage at the inlet is not proportional to the size of the peak velocity reduction in the channel. The largest blockage created a minimum flow speed reduction (K = 0.98) for a channel width of 200mm. It was outperformed by the smallest blockage for a channel width of 300mm where a greater speed reduction was observed (K = 1.04). It was found that for buildings nearing the interaction flow regime the addition of a blockage has negligible effect on speed. 

2017 
Silvestri A, Ghanadi F, Arjomandi M, Cazzolato B, Zander A, 'The effect of the backing cavity on the control of the turbulent boundary layer by the application of a cavity array', 10th International Symposium on Turbulence and Shear Flow Phenomena, TSFP 2017 (2017) The streamwise velocity fluctuations within a fully developed turbulent boundary layer has been investigated downstream of a flushedsurface cavity array underneath a flat plate. ... [more] The streamwise velocity fluctuations within a fully developed turbulent boundary layer has been investigated downstream of a flushedsurface cavity array underneath a flat plate. The size of the holes in the cavity array were selected to be comparable with the dimensions of the expected coherent structures, based on the friction velocity. This study investigates the effect of the backing cavity volume on attenuation of turbulent energy production within the logarithmic region of the turbulent boundary layer. To this end the turbulence intensity profile and sweep attenuation for three different backing cavity volume have been investigated. All measurements were taken in a closedloop low turbulence wind tunnel at two different free stream velocities. The results show that when the backing cavity's volume is equal to V+=3×103 the turbulence intensity and sweep intensity are reduced by up to 8% and 7.2% respectively. From this investigation it has been shown that the dampening of sweep events is not solely due to the walls of each individual cavity.


2017 
Ghanadi F, Emes M, Yu J, Arjomandi M, Kelso R, 'Investigation of the Atmospheric Boundary Layer Characteristics on Gust Factor for the Calculation of Wind Load', INTERNATIONAL CONFERENCE ON CONCENTRATING SOLAR POWER AND CHEMICAL ENERGY SYSTEMS (SOLARPACES 2016), Masdar Inst Sci & Technol, Abu Dhabi, U ARAB EMIRATES (2017)


2017 
Ghanadi F, Yu J, Emes M, Arjomandi M, Kelso R, 'Numerical Investigation of Wind Loads on an Operating Heliostat', INTERNATIONAL CONFERENCE ON CONCENTRATING SOLAR POWER AND CHEMICAL ENERGY SYSTEMS (SOLARPACES 2016), Masdar Inst Sci & Technol, Abu Dhabi, U ARAB EMIRATES (2017)


2016 
Emes MJ, Ghanadi F, Arjomandi M, Kelso RM, 'An experimental technique for the generation of largescale spanwise vortices in a wind tunnel', Proceedings of the 20th Australasian Fluid Mechanics Conference, AFMC 2016 (2016) © 2006 Australasian Fluid Mechanics Society. All rights reserved. The presence of largescale vortices with high spanwise coherence has been observed in the atmospheric boundary l... [more] © 2006 Australasian Fluid Mechanics Society. All rights reserved. The presence of largescale vortices with high spanwise coherence has been observed in the atmospheric boundary layer (ABL). This study investigates an innovative technique to generate a largescale spanwise vortex from the oscillation of a surfacemounted fence in a wind tunnel. Characteristics of the large vortex with a welldefined length scale and its development with downstream distance behind the fence were investigated. Timeaveraged profiles of velocity, normal and Reynolds stresses were measured to determine the dominant frequencies of the large vortices in the wake of the oscillating fence. Longitudinal length scales of the spanwise vortices were calculated using the autocorrelation of velocity data. It was found that the size of the largest spanwise vortices are most significantly influenced by the height of the fence, such that the integral length scales increased by 52mm for a 20mm increase in fence height. Spanwise vortices were also found to be 11mm larger when oscillating the fence at the vortex shedding frequency behind a stationary fence. The oscillation amplitude of the fence was found to have a negligible effect on the size of the large spanwise vortices. 

2016 
Silvestri A, Ghanadi F, Arjomandi M, Cazzolato BS, Zander AC, 'Control of the turbulent boundary layer by the application of a cavity array', Proceedings of the 20th Australasian Fluid Mechanics Conference, AFMC 2016 (2016) © 2006 Australasian Fluid Mechanics Society. All rights reserved. The results presented in this paper provide an insight into the effect of a cavity array on the turbulence produc... [more] © 2006 Australasian Fluid Mechanics Society. All rights reserved. The results presented in this paper provide an insight into the effect of a cavity array on the turbulence production within a turbulent boundary layer. In the present study, the turbulent energy production within a fully developed turbulent boundary layer has been reduced using a flushedsurface cavity array underneath a flat plate coupled with an acoustic actuator. The size of the holes in the cavity array were selected to be comparable with the dimensions of the expected coherent structures, based on the friction velocity. Experimental measurements were taken in a wind tunnel at a number of locations along the array in the streamwise direction and at a variety of acoustic frequencies generated by the acoustic actuator. A maximum turbulence intensity and sweep intensity reduction of 11% and 10% respectively occurred at Re¿ = 3.771 × 103 in the logarithmic region of the boundary layer when no drive frequency was provided. From this investigation it has been shown that the drive frequency of the acoustic actuator has no effect on the turbulence reduction by the cavity array. Instead the physical parameters of the array, including the number and diameter of the cavities in the array have a much more significant effect.


2016 
Yu JS, Arjomandi M, Ghanadi F, Kelso R, 'The effect of inclination angle on the flow characteristics of tandem bluff plates', Proceedings of the 20th Australasian Fluid Mechanics Conference, AFMC 2016 (2016) © 2006 Australasian Fluid Mechanics Society. All rights reserved. The flow around bluff bodies in tandem is of significant interest due to its broad range of applications. Past st... [more] © 2006 Australasian Fluid Mechanics Society. All rights reserved. The flow around bluff bodies in tandem is of significant interest due to its broad range of applications. Past studies have investigated the effect of common geometry configurations such as bluff plates and cylinders and found that flow characteristics varied significantly dependent upon certain geometrical parameters such as bluff body size or spacing ratios. This work explores an unobserved area to determine the effect of inclination angle on the flow around tandem bluff bodies due to an expected change in the pattern of the shed vortices. Specifically, key flow characteristics such as velocity fluctuations and drag are investigated for a pair of flat plates with equal dimensions at a Reynolds number of 54,000. The results are complimented by numerical modelling through computational fluid dynamics using Large Eddy Simulation, where vortex structures are visualized and quantitative drag are validated for. Strouhal number plots show that the inclination angle has a significant effect on the flow interactions between tandem bluff plates, and that when inclined, known transitions between flow regimes no longer occur. The results show that when the shear layer from an upstream bluff body does not meet at the downstream body at any location, a drag reduction is not possible and no optimum gap ratios can be achieved to minimize drag.


2016 
Silvestri A, Ghanadi F, Arjomandi M, Cazzolato BS, Zander AC, 'Control of the turbulent boundary layer by the application of a cavity array', Proceedings of the 20th Australasian Fluid Mechanics Conference, AFMC 2016 (2016) © 2006 Australasian Fluid Mechanics Society. All rights reserved. The results presented in this paper provide an insight into the effect of a cavity array on the turbulence produc... [more] © 2006 Australasian Fluid Mechanics Society. All rights reserved. The results presented in this paper provide an insight into the effect of a cavity array on the turbulence production within a turbulent boundary layer. In the present study, the turbulent energy production within a fully developed turbulent boundary layer has been reduced using a flushedsurface cavity array underneath a flat plate coupled with an acoustic actuator. The size of the holes in the cavity array were selected to be comparable with the dimensions of the expected coherent structures, based on the friction velocity. Experimental measurements were taken in a wind tunnel at a number of locations along the array in the streamwise direction and at a variety of acoustic frequencies generated by the acoustic actuator. A maximum turbulence intensity and sweep intensity reduction of 11% and 10% respectively occurred at Re¿ = 3.771 × 103 in the logarithmic region of the boundary layer when no drive frequency was provided. From this investigation it has been shown that the drive frequency of the acoustic actuator has no effect on the turbulence reduction by the cavity array. Instead the physical parameters of the array, including the number and diameter of the cavities in the array have a much more significant effect.


2016 
Emes MJ, Ghanadi F, Arjomandi M, Kelso RM, 'An experimental technique for the generation of largescale spanwise vortices in a wind tunnel', Proceedings of the 20th Australasian Fluid Mechanics Conference, AFMC 2016 (2016) © 2006 Australasian Fluid Mechanics Society. All rights reserved. The presence of largescale vortices with high spanwise coherence has been observed in the atmospheric boundary l... [more] © 2006 Australasian Fluid Mechanics Society. All rights reserved. The presence of largescale vortices with high spanwise coherence has been observed in the atmospheric boundary layer (ABL). This study investigates an innovative technique to generate a largescale spanwise vortex from the oscillation of a surfacemounted fence in a wind tunnel. Characteristics of the large vortex with a welldefined length scale and its development with downstream distance behind the fence were investigated. Timeaveraged profiles of velocity, normal and Reynolds stresses were measured to determine the dominant frequencies of the large vortices in the wake of the oscillating fence. Longitudinal length scales of the spanwise vortices were calculated using the autocorrelation of velocity data. It was found that the size of the largest spanwise vortices are most significantly influenced by the height of the fence, such that the integral length scales increased by 52mm for a 20mm increase in fence height. Spanwise vortices were also found to be 11mm larger when oscillating the fence at the vortex shedding frequency behind a stationary fence. The oscillation amplitude of the fence was found to have a negligible effect on the size of the large spanwise vortices. 

2016 
Yu JS, Arjomandi M, Ghanadi F, Kelso R, 'The effect of inclination angle on the flow characteristics of tandem bluff plates', Proceedings of the 20th Australasian Fluid Mechanics Conference, AFMC 2016 (2016) © 2006 Australasian Fluid Mechanics Society. All rights reserved. The flow around bluff bodies in tandem is of significant interest due to its broad range of applications. Past st... [more] © 2006 Australasian Fluid Mechanics Society. All rights reserved. The flow around bluff bodies in tandem is of significant interest due to its broad range of applications. Past studies have investigated the effect of common geometry configurations such as bluff plates and cylinders and found that flow characteristics varied significantly dependent upon certain geometrical parameters such as bluff body size or spacing ratios. This work explores an unobserved area to determine the effect of inclination angle on the flow around tandem bluff bodies due to an expected change in the pattern of the shed vortices. Specifically, key flow characteristics such as velocity fluctuations and drag are investigated for a pair of flat plates with equal dimensions at a Reynolds number of 54,000. The results are complimented by numerical modelling through computational fluid dynamics using Large Eddy Simulation, where vortex structures are visualized and quantitative drag are validated for. Strouhal number plots show that the inclination angle has a significant effect on the flow interactions between tandem bluff plates, and that when inclined, known transitions between flow regimes no longer occur. The results show that when the shear layer from an upstream bluff body does not meet at the downstream body at any location, a drag reduction is not possible and no optimum gap ratios can be achieved to minimize drag.


2016 
Coventry J, Arjomandi M, Barry J, Blanco M, Burgess G, Campbell J, et al., 'Development of the ASTRI Heliostat', SOLARPACES 2015: INTERNATIONAL CONFERENCE ON CONCENTRATING SOLAR POWER AND CHEMICAL ENERGY SYSTEMS, Cape Town, SOUTH AFRICA (2016)


2015 
Ghanadi F, Arjomandi M, Cazzolato B, Zander A, 'Effectiveness of flowexcited Helmholtz resonator on turbulence structures in streamwise and spanwise directions', 9th International Symposium on Turbulence and Shear Flow Phenomena, TSFP 2015 (2015) This paper evaluates the capability of a flowexcited cylindrical Helmholtz resonator for the manipulation of the disturbances within a three dimensional turbulent boundary layer ... [more] This paper evaluates the capability of a flowexcited cylindrical Helmholtz resonator for the manipulation of the disturbances within a three dimensional turbulent boundary layer in the streamwise and spanwise directions. A detailed investigation of the characteristics of the boundary layer downstream of the resonator has been accomplished through an extensive experimental study. The results showed that a reduction in the turbulence intensity of the streamwise velocity fluctuations and sweep events occurs immediately downstream of the resonator but this effect dissipates further away from the resonator orifice. This was hypothesized to be due to thinning of the boundary layer thickness downstream of the resonator in the streamwise direction and weakening of the spanwise vortices generated by the resonator. The results presented in this paper provide an improved understanding for further development of multiple adjacent resonators over an area as a possible alternative system for the purpose of turbulent flow control.


2014 
Ghanadi F, Arjomandi M, Cazzolato BS, Zander AC, 'Experimental investigation of the application of a selfexcited cylindrical Helmholtz resonator for turbulent drag reduction', Proceedings of the 19th Australasian Fluid Mechanics Conference, AFMC 2014 (2014) An experimental investigation has been undertaken to investigate the suppression of the turbulent events within a boundary layer by different Helmholtz resonators. The flushmount... [more] An experimental investigation has been undertaken to investigate the suppression of the turbulent events within a boundary layer by different Helmholtz resonators. The flushmounted cylindrical resonators were installed within a flat plate and excited by a fully developed turbulent boundary layer. The characteristics of the oncoming boundary layer and the velocity fluctuations in the vicinity of the orifice were measured using hotwire anemometry. A 12% reduction in turbulent intensity was observed downstream of the resonator for the case when the ratio of the resonator orifice length to the boundary layer thickness was approximately unity. This was accompanied by 5% reduction in sweep intensity. When the diameter and length of the resonator orifice are approximately equal to the thickness of the inner layer, =300, the velocity fluctuations are more positive and spiky resulting in an 11% reduction in sweep intensity. Attenuation of the turbulence production demonstrates the potential of the flowexcited Helmholtz resonator as a novel flow control device.


2012 
Ghanadi F, Arjomandi M, Zander AC, Cazzolato BS, 'A review of skin friction drag reduction within the turbulent boundary layer', Advances in Applied Mechanics Research, Conference Proceedings  7th Australasian Congress on Applied Mechanics, ACAM 2012 (2012) Skin friction drag reduction in the turbulent boundary layer has high potential benefits which have been a subject of much interest. From general point of view this paper gives an... [more] Skin friction drag reduction in the turbulent boundary layer has high potential benefits which have been a subject of much interest. From general point of view this paper gives an overview of various methods to control the turbulent boundary layer. Primary section of the paper highlights the importance of skin friction drag reduction in turbulent boundary layers, followed by brief discussion of turbulence and Reynolds shear stress production process in the near wall region. Since there are several ways to suppress the instabilities, which naturally occur in the turbulent boundary layer, lots of control techniques have been investigated in next sections. The present article provides an uptodate summary of passive and active mechanisms responsible for viscous drag reduction. Furthermore, the implications of previous controller and the success or limitations of various methods are discussed.


2006 
Yu JS, Arjomandi M, Ghanadi F, Kelso R, 'The effect of inclination angle on the flow characteristics of tandem bluff plates', Proceedings of the 20th Australasian Fluid Mechanics Conference, AFMC 2016 (2006) © 2006 Australasian Fluid Mechanics Society. All rights reserved. The flow around bluff bodies in tandem is of significant interest due to its broad range of applications. Past st... [more] © 2006 Australasian Fluid Mechanics Society. All rights reserved. The flow around bluff bodies in tandem is of significant interest due to its broad range of applications. Past studies have investigated the effect of common geometry configurations such as bluff plates and cylinders and found that flow characteristics varied significantly dependent upon certain geometrical parameters such as bluff body size or spacing ratios. This work explores an unobserved area to determine the effect of inclination angle on the flow around tandem bluff bodies due to an expected change in the pattern of the shed vortices. Specifically, key flow characteristics such as velocity fluctuations and drag are investigated for a pair of flat plates with equal dimensions at a Reynolds number of 54,000. The results are complimented by numerical modelling through computational fluid dynamics using Large Eddy Simulation, where vortex structures are visualized and quantitative drag are validated for. Strouhal number plots show that the inclination angle has a significant effect on the flow interactions between tandem bluff plates, and that when inclined, known transitions between flow regimes no longer occur. The results show that when the shear layer from an upstream bluff body does not meet at the downstream body at any location, a drag reduction is not possible and no optimum gap ratios can be achieved to minimize drag.


2006 
Emes MJ, Ghanadi F, Arjomandi M, Kelso RM, 'An experimental technique for the generation of largescale spanwise vortices in a wind tunnel', Proceedings of the 20th Australasian Fluid Mechanics Conference, AFMC 2016 (2006) © 2006 Australasian Fluid Mechanics Society. All rights reserved. The presence of largescale vortices with high spanwise coherence has been observed in the atmospheric boundary l... [more] © 2006 Australasian Fluid Mechanics Society. All rights reserved. The presence of largescale vortices with high spanwise coherence has been observed in the atmospheric boundary layer (ABL). This study investigates an innovative technique to generate a largescale spanwise vortex from the oscillation of a surfacemounted fence in a wind tunnel. Characteristics of the large vortex with a welldefined length scale and its development with downstream distance behind the fence were investigated. Timeaveraged profiles of velocity, normal and Reynolds stresses were measured to determine the dominant frequencies of the large vortices in the wake of the oscillating fence. Longitudinal length scales of the spanwise vortices were calculated using the autocorrelation of velocity data. It was found that the size of the largest spanwise vortices are most significantly influenced by the height of the fence, such that the integral length scales increased by 52mm for a 20mm increase in fence height. Spanwise vortices were also found to be 11mm larger when oscillating the fence at the vortex shedding frequency behind a stationary fence. The oscillation amplitude of the fence was found to have a negligible effect on the size of the large spanwise vortices. 

2006 
Silvestri A, Ghanadi F, Arjomandi M, Cazzolato BS, Zander AC, 'Control of the turbulent boundary layer by the application of a cavity array', Proceedings of the 20th Australasian Fluid Mechanics Conference, AFMC 2016 (2006) © 2006 Australasian Fluid Mechanics Society. All rights reserved. The results presented in this paper provide an insight into the effect of a cavity array on the turbulence produc... [more] © 2006 Australasian Fluid Mechanics Society. All rights reserved. The results presented in this paper provide an insight into the effect of a cavity array on the turbulence production within a turbulent boundary layer. In the present study, the turbulent energy production within a fully developed turbulent boundary layer has been reduced using a flushedsurface cavity array underneath a flat plate coupled with an acoustic actuator. The size of the holes in the cavity array were selected to be comparable with the dimensions of the expected coherent structures, based on the friction velocity. Experimental measurements were taken in a wind tunnel at a number of locations along the array in the streamwise direction and at a variety of acoustic frequencies generated by the acoustic actuator. A maximum turbulence intensity and sweep intensity reduction of 11% and 10% respectively occurred at Re¿ = 3.771 × 103 in the logarithmic region of the boundary layer when no drive frequency was provided. From this investigation it has been shown that the drive frequency of the acoustic actuator has no effect on the turbulence reduction by the cavity array. Instead the physical parameters of the array, including the number and diameter of the cavities in the array have a much more significant effect. 

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Grants and Funding
Summary
Number of grants  1 

Total funding  $540,000 
Click on a grant title below to expand the full details for that specific grant.
20201 grants / $540,000
Microperforation for passive drag reduction$540,000
Funding body: ARC (Australian Research Council)
Funding body  ARC (Australian Research Council) 

Project Team  Associate Professor Maziar Arjomandi, Professor Benjamin Cazzolato, Dr Farzin Ghanadi, Professor Beverley McKeon, Professor Bharath Ganapathisubramani 
Scheme  ARC Discovery 
Role  Investigator 
Funding Start  2020 
Funding Finish  2022 
GNo  
Type Of Funding  C1200  Aust Competitive  ARC 
Category  1200 
UON  N 
Dr Farzin Ghanadi
Position
Research Associate
School of Engineering
College of Engineering, Science and Environment
Contact Details
farzin.ghanadi@newcastle.edu.au  
Phone  (02) 4985 4938 
Office
Room  ES302 

Building  Engineering S (ES) 
Location  Callaghan University Drive Callaghan, NSW 2308 Australia University Drive Callaghan, NSW 2308 Australia 