Multiscale Numerical Simulation of Fluid-Solid Interaction

Abstract

A new multiscale numerical method is developed to simulate the fluid-solid interaction. The solid motion is described by coarse grained particles which are generated by consolidation of harmonically interacting atoms, and the fluid motion is by the lattice Boltzmann method. Since the characteristic time of the fluid motion is much longer than that of the coarse grained particles, the momentum change due to the rapid collision of the coarse grained particles at the interface is accumulated over a certain time duration and then passed the fluid motion. The method is applied to an elastic rod fixed on the wall in the two dimensional Poiseuille flow. The oscillation and stress within the rod as well as the velocity and vorticity of the fluid are examined with respect to the vortex shedding at the top of the rod. Also the method is applied to the problem of fluid transfer by multiple elastic rods. It is found that the results are quite reasonable and that the present method is effective in dealing with the fluid-solid interactions.