A 3D Variational BEM Formulation for Fluid-Structure Interaction in Viscous Compressible Flow

This paper is aimed at presenting recent advances in modeling and simulation of vibrating structures in presence of external as well as of internal fluid flows using methods based on symmetric variational BEM formulation coupled with the FE. The structural weak form is coupled with a novel boundary element variational formulation of a compressible viscous fluid. The proposed formulation has distinct advantages: (i) over the classical FE, it avoids the discretisation of the fluid domain; (ii) over the collocation BEM formulation, it avoids the explicit calculation of the finite part of hypersingular integrals. Also, the discretisation, by the boundary finite element procedure, of the resulting mixed variational functional leads to a symmetric algebraic system. A computer code based on these concepts has been developed and applied to calculate 3D vibroacoustic behavior of various coupled mechanical systems.