Mr Bruce Cartwright

Experimental wave generation in channels is usually achieved through wavemakers (moving paddles) acting on the surface of the water. Although practical for engineering purposes, wavemakers have issues: they perform poorly in the generation of long waves and create evanescent waves in their vicinity. In this article, we introduce a framework for wave generation through the action of an underwater multipoint mechanism: the pedal-wavemaking method. Our multipoint action makes each point of the bottom move with a prescribed pedalling-like motion. We analyse the linear response of waves in a uniform channel in terms of the wavelength of the bottom action. The framework naturally solves the problem of the performance for long waves and replaces evanescent waves by a thin boundary layer at the bottom of the channel. We also show that proper synchroni-sation of the orbital motion on the bottom can produce waves that mimic deep water waves. This last feature has been proved to be useful to study fluid¿structure interaction in simulations based on smoothed particle hydrodynamics.

This paper discusses selected features of the Smoothed Particle Hydrodynamics (SPH) method when used in combination with a Finite Element (FE) software tool. Special attention is paid to the implementation of wall boundary conditions in view of their relevance to the simulation of fluid-structure interaction (FSI). Several industrial applications of the hybrid SPH-FE method are reviewed in detail. These include the ditching of a fixed-wing aircraft, the ditching of a helicopter with an Emergency Flotation System, and the flooding of a ship due to a breach in the hull. The comparison of the results of the numerical study on fixed-wing aircraft against experimental data demonstrate the validity of the SPH method. It is concluded that the SPH-FE approach is well-suited for the simulation of violent flow phenomena and fluid-structure interaction.

Over the last few decades, the Smoothed Particle Hydrodynamics (SPH) method has gained popularity as a mesh-less method to simulate fluid flows. In contrast, the finite element (FE) method remains the preferred tool to simulate structural deformation. This paper presents a coupled SPH-FE software tool useful for a large variety of dynamic fluid flow simulations and fluid-structure interaction. Several recent developments in the SPH algorithm are presented as well as a few studies demonstrating the validity in comparison to experimental data. Following a brief overview of industrial applications of the hybrid SPH-FE method, three computational studies are discussed in greater detail. These concern ships in waves, gearbox lubrication and cardiovascular flow. It is shown that the SPH-FE approach is well-suited for violent flow phenomena and fluid-structure interaction.