Coupled BEM–MLPG acoustic analysis for non-homogeneous media

A technique that couples the boundary element method (BEM) with the meshless local Petrov–Galerkin (MLPG) method is proposed to simulate the 2-D acoustic wave propagation in an unbounded fluid domain containing confined subdomains where the material properties vary from point to point.The non-homogeneous confined subdomains are only discretized with nodal points and treated by the MLPG. The nodal points, which are placed at the interface between the confined subdomains and the unbounded homogenous acoustic fluid, are used to couple the BEM and the MPLG. The moving least-squares (MLS) approximation scheme is used to provide the approximation of field quantities.The proposed BEM–MLPG coupled approach is verified against the results provided by an analytical solution developed for a circular confined subdomain, in which the velocity variation within the circular non-homogeneous region only occurs in the radial direction. A numerical example illustrates the application of the proposed approach to solve the case of a pair of non-homogeneous confined subdomains, for which analytical solutions are not known.