A Boundary Element Method For Propagation Over Absorbing Boundaries

Abstract Two-dimensional sound propagation over an arbitrarily shaped barrier situated on a locally reacting infinite plane in a homogeneous medium is treated using the boundary element method (BEM). The boundary integral equation (BIE) is formulated in terms of a half-space Green's function which is constructed to satisfy the impedance boundary condition on the ground plane. The integral in the resulting Green's function is transformed, using the steepest descent method, to a suitable form for effective numerical evaluation even for a relatively small distance between the image source and the receiving point. Comparison of the BEM results with an available analytic solution and experimental results by Kearns and by Habault shows good agreement to the sound field using the BEM.