A DRBEM model for sound waves propagation in an inhomogeneous medium

The Dual Reciprocity Boundary Element Method (DRBEM) is applied to sound wave propagation problems in non homogeneous medium either in a closed or an infinite domain, for which it is particularly well fitted. The equation to be solved is a Poisson equation and the inhomogeneities are treated as a source term, which is represented as a serie with unknown coefficients and known interpolation functions. Making use of the Green's third formula, the volume integrals can be converted into surface ones. Application to finite or infinite domains with temperature or velocity gradients shows the ability of the method.