Acoustic Scattering from Two- and Three-Dimensional Bodies

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