A CFD-based high-order Discontinuous Galerkin solver for three dimensional electromagnetic scattering problems

Abstract

In this paper, a CFD (Computational Fluid Dynamics) based DG (Discontinuous Galerkin) method is introduced to solve the three-dimensional Maxwell’s equations for complex geometries on unstructured grids. In order to reduce the computing expense, both the quadrature-free implementation method and the parallel computing based on domain decomposition are employed. On the far-field boundary, the non-reflecting boundary condition is implemented. Numerical integration rather than the quadrature-free implementation is used over the faces on the solid boundary to implement the electromagnetic solid boundary condition for perfectly conducting objectives. Both benchmark examples and complex geometry case are tested with the CFD-based DG solver. Numerical results indicate that highly accurate results can be obtained when using high order even on coarse grid and the present method is very suitable for complex geometries. Furthermore, the costs of CPU time and the speedup of the parallel computation are also evaluated.