AN ITERATIVE SOLVER OF THE HELMHOLTZ INTEGRAL-EQUATION FOR HIGH-FREQUENCY ACOUSTIC SCATTERING

High-frequency scattering from convex and non-convex bodies is studied using an iterative algorithm. The key point of the method is a self-a djoint formulation of the Helmholtz integral equation, which ensures t he convergence of the iteration process toward the true solution. For all investigated structures with different surface impedances fast con vergence could be observed. The number of surface elements of the scat terer varies from about 6000 to 60 000 and the calculations are perfor med in the high-frequency range with Helmholtz numbers ka between 20 a nd 63. Even for a scattering structure with nearly 60 000 boundary ele ments, all computations could be carried out on a regular personal com puter. (C) 1998 Acoustical Society of America. [S0001-4966(98)01202-8] .