A Plane Wave Discontinuous Galerkin Method with a Dirichlet-to-Neumann Boundary Condition for the Scattering Problem in Acoustics

TL;DR

This paper develops a Plane Wave Discontinuous Galerkin method for acoustic scattering problems, incorporating a non-local Dirichlet-to-Neumann boundary condition to improve accuracy and provide error estimates.

Contribution

It introduces a novel PWDG approach with DtN boundary conditions and derives error estimates related to truncation and mesh size.

Findings

Numerical results show improved accuracy with DtN boundary conditions.

Error estimates are established for the method.

The method effectively handles exterior acoustic scattering problems.

Abstract

We consider the numerical solution of an acoustic scattering problem by the Plane Wave Discontinuous Galerkin Method (PWDG) in the exterior of a bounded domain in $\mathbb{R}^2$. In order to apply the PWDG method, we introduce an artificial boundary to truncate the domain, and we impose a non-local Dirichlet-to-Neumann (DtN) boundary conditions on the artificial curve. To define the method, we introduce new consistent numerical fluxes that incorporate the truncated series of the DtN map. Error estimates with respect to the truncation order of the DtN map, and with respect to mesh width are derived. Numerical results suggest that the accuracy of the PWDG method for the acoustic scattering problem can be significantly improved by using DtN boundary conditions.