Abstract
An iterative domain decomposition method for the numerical solution of an external problem of the Helmholtz equation is considered. An artificial boundary decomposes the external domain Ω into a bounded subdomain Ω_1 and the unbounded subdomain Ω_2 outside Ω_1. We apply the Dirichlet-Neumann map on the boundary. The finite element and the boundary element methods are used for the discretization of the equations on the domains Ω_1 and Ω_2 respectively, and the methods are indirectly combined by the nodal data along the artificial boundary. Numerical examples show that our method is applicable for low frequency waves and the upper limit of tractable frequencies depends in polynomial order on the radius of the artificial boundary.
