Implementing highly accurate non-reflecting boundary conditions for large scale problems in structural acoustics

Abstract

Time-harmonic problems of acoustic radiation and scattering in unbounded domains are governed by the Helmholtz equation in the fluid domain, coupled to the structural equations for elastic bodies in contact with the fluid. In addition to the boundary conditions applied to the structure and the fluid-structure interface conditions, a radiation condition is applied at infinity to render the solution to the problem unique. When modeling such problems with domain based methods such as the finite element method, the finite element mesh is truncated at a finite distance from the structure and either an artificial boundary condition that replicates the infinite domain is applied, or special elements such as infinite elements are used.