A MIXED DISPLACEMENT-BASED FINITE-ELEMENT FORMULATION FOR ACOUSTIC FLUID-STRUCTURE INTERACTION

The solutions of fluid-structure interaction problems, using displacem ent-based finite element formulations for acoustic fluids, may contain spurious non-zero frequencies. To remove this deficiency, we present here a new formulation based on a three-field discretization using dis placements, pressure and a ''vorticity moment'' as variables with an a ppropriate treatment of the boundary conditions. We propose specific f inite element discretizations and give the numerical results of variou s example problems.