DtN and NtD surface radiation conditions for two-dimensional acoustic scattering: Formal derivation and numerical validation

The aim of this paper is to derive and evaluate new approximations of the Dirichlet-to-Neumann (DtN) and Neumann-to-Dirichlet (NtD) maps for two-dimensional acoustic scattering problems. Some formal approximations for the two-dimensional case are derived. These various approximations are next numerically validated and compared.