Multirate technique for explicit Discontinuous Galerkin computations of time domain Maxwell equations on complex geometries

Abstract : This paper presents a multirate technique to improve and optimize the time step of a second order 2-stages Explicit Runge-Kutta scheme (ERK). In this technique, the mesh elements are stored in different groups according to their stable time steps. These groups are sorted into two classes. The bulk groups where the 2-stages ERK method is applied once or repeatedly. The buffer groups that used to accommodate transition between two bulks groups. This technique is proposed for accelerating explicit discontinuous Galerkin computations of time domain Maxwell equations. An application example on human skull is proposed to show the efficiency of this technique to simulate wave propagation on complex geometries.