Acoustic scattering from two- and three-dimensional bodies

In this paper we consider the scattering of sound by two- and three-dimensi onal bodies with arbitrary geometries. Particular emphasis is placed on the methodology for the implementation of solid wall boundary conditions for h igh-order, high-bandwidth numerical schemes. The Impedance Mismatch Method (IMM) is introduced to treat solid wall boundaries. In this method the soli d wall is simulated using a wall region in which the characteristic impedan ce is set to a different value from that in the fluid region. This method h as many advantages over traditional solid wall boundary treatments, includi ng simplicity of coding, speed of computation and the ability to treat curv ed boundaries. This method has been used to solve a number of acoustic scat tering problems to demonstrate its effectiveness. These problems include ac oustic reflections from an infinite plate, acoustic scattering from a two-d imensional finite plate and a cylinder, and acoustic scattering by a sphere and a cylindrical shell.