An efficient boundary element algorithm for multi-frequency acoustical analysis

In this article, a new boundary element algorithm in acoustics is proposed. This new algorithm uses a so-called “Green’s function interpolation technique” so that it is ideally suited to a multi-frequency analysis. In the numerical implementation of this new algorithm, the Green’s function used in the boundary integral equation is interpolated by a set of shape functions. Numerical integration is then confined to a frequency-independent part only, and hence, is carried out only once at the first frequency of a multi-frequency run. At subsequent frequencies, only the nodal values of the Green’s function have to be re-calculated for the formation of the boundary element coefficient matrices. Compared to the recently developed “frequency interpolation technique,” this new algorithm requires much less disk space and can be easily extended to half-space problems and problems with planes of symmetry.