A NONSINGULAR BOUNDARY INTEGRAL-EQUATION FOR ACOUSTIC PROBLEMS

A weakly singular boundary integral equation and a non-singular one ar e derived for acoustic problems. By using the one-dimensional wave pro pagation mode, the degree of the singularities appearing in the conven tional boundary integral equation can be reduced. Since the strong sin gularity is removed in the weakly singular equation, the jump term of the field pressure expression in the very vicinity of the boundary dis appears. It is shown that the weak singularity can be also removed for a smooth boundary in the non-singular representation, and thus specia l treatments for singular integral are no longer needed. In order to t est the proposed method, several simple problems have been solved by e mploying the triangular element with standard Gaussian quadrature inte gration points. The results obtained show the accuracy of the method i n the near field as well as on the boundary. (C) 1996 Academic Press L imited