Development of a numerical tool to deal with complex fluid/structure interactions: applications in energy efficiency, biomechanics and marine propulsion

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The long-term objective of this research program is to develop a new numerical CFD (Computational Fluid Dynamics) tool to investigate complex flow systems involving fluid/structure interactions. It will be then applied to four concrete situations in the fields of energy efficiency, biomechanics and marine propulsion.***In various situations, one may find a solid body moving in a superimposed fluid flow. The solid body motion may be prescribed (« one-way coupling ») or induced by the fluid flow (« two-way coupling »).***In 2014, the development of an in-house numerical tool based on the Lattice Boltzmann method and coupled to an immersed boundary method to take into account the solid body motion has been initiated. This kind of coupled approach has many advantages: adaptative mesh grids are not required, the accuracy of the spatial numerical schemes is preserved even at the walls and the introduction of new physical effects is achieved easily by changing viscosity and/or by adding external body forces in the Boltzmann equation. The present version of the code enables to simulate flow configurations including a solid body with an imposed motion in a two-phase stratified fluid medium with slightly different densities and for arbitrary (de)wetting conditions.***In the next five years, my research program will focus on numerical developments of the CFD tool to simulate more realistic flow configurations, including: non-Newtonian fluids, turbulence, "two-way coupling" for the fluid/structure interaction, poro-elastic walls and effect of a magnetic field. This new CFD tool will be applied to three strategic research fields in mechanical engineering:***1/ in energy efficiency for the optimization of two refrigeration systems: a porous regenerator used in magnetic refrigeration and a system generator/storage tank for ice slurries.****2/ in biomechanics to study the transport of bronchial mucus in the human respiratory system by the synchronyzed beating of cilia at the epithelium surface.****3/ in marine propulsion by the use of Flettner rotors. These are high rotating cylinders using the Magnus effect to induce a streamwise power enabling to save about 25% of the total energy required for ship propulsion.***This code will be the first to allow the simulation of the fluid/structure interactions in such complex situations while preserving the accuracy of the results on the moving walls. In addition to the four applications covered by the program, this unique tool will open the door with many other applications: the geometrical optimization of water and wind turbines, the propulsion by ciliary motion of marine animals and the transport of the red cells among other things. Six highly qualified personnel implied not only in the numerical developments but also in the real applications developed at the partners, will be trained during the program.***