THE INFINITE BOUNDARY ELEMENT AND ITS APPLICATION TO THE UNBOUNDED HELMHOLTZ PROBLEM

The combination method, combined finite element-boundary element approach, is suitable for unbounded field problems. Although this technique attains a high degree of accuracy, the matrix of the discretized system equation is not banded but sometimes densely or sparsely populated. We reported the development of an infinite boundary element for 2-D Laplace problems, with which the bandwidth of the discretized system matrix does not increase beyond that of the finite element region. In this paper, we extend this approach and propose another infinite boundary element for 2-D Helmholtz problems. To illustrate the validity of the proposed technique, some numerical examples are given and their results are compared with those of other methods.