A modified dual-level fast multipole boundary element method based on the Burton-Miller formulation for large-scale three-dimensional sound field analysis

Large-scale sound field analysis is a difficult task for numerical simulations. In this study, a modified dual-level fast multipole boundary element method is proposed for analyzing this challenging problem. The proposed method is based on the Burton-Miller formulation to overcome the non-uniqueness issues in exterior acoustic problems. By transforming the fully-populated matrix formed from fine mesh to a large-scale locally supported sparse matrix induced from coarse mesh, the method overcomes computational bottleneck of the boundary element method originating from excessive storage requirements and the large number of operations. In this article, we further combine the method with the fast multipole method to expedite its matrix vector multiplications process. By testing the method to a series of complicated engineering cases, it is observed that the method performs 44% faster than COMSOL in the analysis of acoustic scattering characteristics of an A-320 aircraft. In the analysis of underwater acoustic scattering characteristics of the Kilo-class submarine, the method is 56% faster than the traditional fast multipole boundary element method.