The model that underlies the BERIM method models the acoustic field in a cavity with one opening. A recent paper describing the method in more detail and demonstrating its application to the acoustic field produced by a horn loudspeaker is given in the following link.
Simulation of the Acoustic Field of a Horn Loudspeaker by the Boundary Element–Rayleigh Integral Method
The Fortran (77) subroutine BERIM3 implements the Boundary Element - Rayleigh Integral for general 3D problems: BERIM3 delivers a computational solution to the acoustic field produced by an open cavity.
[ BERIM3]: BERIM3 Subroutine. [ BERIM3_T]: BERIM3 Test Program
Utility routines: [ H3LC] [ CGLS] [ GEOM3D]
For axisymmetric problems we have BERIMA:
[ BERIMA]: BERIMA Subroutine. [ BERIMA_T]: BERIMA Test Program
Utility routines: [ H3ALC] [ CGLS] [ GEOM2D] [ GEOM3D]
[ GEOM2D.FOR ] [ GEOM3D.FOR ]Version 2 with manual (beta release)