A hybrid method combining the edge source integral equation and the boundary element method for scattering problems

Abstract

A hybrid method for acoustic scattering problems is studied in this paper. The boundary element method is combined with a recently developed edge diffraction based method [J. Acoust. Soc. Am. 133, pp. 3681–3691, 2013]. Although the edge diffraction method has been shown to provide accurate results for convex, rigid objects at a very attractive computational cost, it has some numerical challenges for certain radiation directions. The hybrid method suggested here has a similar structure as the boundary element method (BEM): in a first step, the sound pressure is calculated on the surface of the scattering object, and in a second step, the scattered sound is obtained at any external receiver point. In this method, the edge diffraction based method is used for the first step, and then, the calculation of the scattered sound is performed à la BEM by means of the Kirkhoff–Helmholtz Integral equation. Several benchmark cases are studied, and the results are compared with different reference methods.