ACCURACY AND EFFICIENCY OF THE MULTIPOLE GALERKIN BEM FOR ACOUSTICS

摘要

The fast multipole method is employed to accelerate the Galerkin boundary element method for acoustics. Important parameters as the nearfield size and the expansion length are discussed and numerical examples are provided. An approximate inverse preconditioner and a preconditioner based on spectral properties of the boundary integral operators are presented. Both approaches prove suitable to reduce the iteration count and to improve the efficiency of the method.