A new domain decomposition method is presented for the exterior Helmholtz p
roblem. The nonlocal Dirichlet-to-Neumann (DW) map is used as a nonreflecti
ng condition on the outer computational boundary. The computational domain
is divided into nonoverlapping subdomains with Sommerfeld-type conditions o
n the adjacent subdomain boundaries to ensure uniqueness. An iterative sche
me is developed, where independent subdomain boundary-value problems are ob
tained by applying the DtN operator to values from the previous iteration.
The independent problems are then discretized with finite elements and can
be solved concurrently. Numerical results are presented for a two-dimension
al model problem, and both the solution accuracy and convergence rate are i
nvestigated. (C) 1998 Academic Press.