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arXiv · 1410.1899

Transparent boundary conditions in a Discontinuous Galerkin Trefftz method

Herbert Egger·Fritz Kretzschmar·Sascha M. Schnepp·Igor Tsukerman·Thomas Weiland
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Abstract

The modeling and simulation of electromagnetic wave propagation is often accompanied by a restriction to bounded domains which requires the introduction of artificial boundaries. The corresponding boundary conditions should be chosen in order to minimize parasitic reflections. In this paper, we investigate a new type of transparent boundary condition for a discontinuous Galerkin Trefftz finite element method. The choice of a particular basis consisting of polynomial plane waves allows us to split the electromagnetic field into components with a well specified direction of propagation. The reflections at the artificial boundaries are then reduced by penalizing components of the field incoming into the space-time domain of interest. We formally introduce this concept, discuss its realization within the discontinuous Galerkin framework, and demonstrate the performance of the resulting approximations by numerical tests. A comparison with first order absorbing boundary conditions, that are frequently used in practice, is made. For a proper choice of basis functions, we observe spectral convergence in our numerical test and an overall dissipative behavior for which we also give some theoretical explanation.

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Herbert Egger, Fritz Kretzschmar, Sascha M. Schnepp, Igor Tsukerman, Thomas Weiland. 2015-05-18. Transparent boundary conditions in a Discontinuous Galerkin Trefftz method. https://arxiv.org/abs/1410.1899

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