A multipole Galerkin boundary element method for acoustics

A fast multilevel multipole (FMM) algorithm is derived for the Helmholtz equation and adopted to the symmetric Galerkin boundary element method (BEM) for acoustics. The FMM allows to evaluate a matrix – vector product of the BEM with a computational cost of OðN log 2 NÞ; thus leading to a significant reduction of computation time and memory requirements compared to standard BEM formulations. This allows the simulation of large scale acoustic models. The performance of the algorithm is demonstrated on the example of sound radiation from an L-shaped domain with BE discretizations of up to 45,000 elements. q 2003 Elsevier Ltd. All rights reserved.