Studies on surface discretization in boundary element method applications

Abstract

The implementation of the boundary element method (BEM) to sound radiation problems consists of discretizing the vibrating surface into a number of elemental radiators and then applying the Helmholtz integral equation for predicting the acoustic field. As with other numerical techniques such as the finite element method, the accuracy of the model is dependent upon, among other factors, the discretization scheme. Creating an efficient mesh is important in order to insure accurate results with a reasonable amount of computational effort. Results of work conducted comparing the use of planar as well as linear and quadratic isoparametric elements are shown. The case studies involve modeling the acoustic field and radiation efficiency of a pulsating sphere at various wavenumbers and modeling the directivity pattern of a vibrating finite cylinder. Procedures for checking accuracy of solution are compared such as matrix condition number and velocity potential of interior points.