Computing the acoustic field of a radiating cavity by the boundary element - Rayleigh integral method (BERIM)

This paper describes the Fortran subroutine BERIM3 that delivers a computational solution to the acoustic field both within and outside of a cavity with one opening into the exterior domain. The mathematical model is based on coupling the usual direct boundary integral equation for the interior region to the Rayleigh integral for the mouth of the domain and the exterior region. The usual boundary element method (BEM) and Rayleigh integral method (RIM) systems of equations are coupled through the application of continuity at the mouth of the cavity. The method is applied to a horn loudspeaker.