Numerical solution of nonlinear exterior wave problems using local absorbing boundary conditions

The method of Absorbing Boundary Conditions (ABCs) is considered for the nu merical solution of a class of nonlinear exterior wave scattering problems. Recently, a scheme based on the exact nonlocal Dirichlet-to-Neumann (DtN) ABC has been proposed for such problems. Although this method is very accur ate, it is also highly expensive computationally. In this paper, the nonloc al ABC is replaced by a low-order focal ABC, which is obtained by localizin g the DtN condition in a certain "optimal" way. The performance of the new local scheme is compared to that of the nonlocal scheme via numerical exper iments in two dimensions.