A divergence cleaning method for the high order DG-FEM in the time domain

We investigate the Discontinuous Galerkin-Finite Element Method (DG-FEM) for the solution of Maxwell´s equations in the time domain. Divergence laws are known to be violated by this formulation, which consequently gives rise to spurious charges in numerical simulations. It is however, possible to impose additional constrains within the framework of DG-FEM and so obtain a “clean” solution spectrum. In this work a divergence cleaning method based on an orthogonal projection into a high order H(curl)-conforming space is proposed. The method separates spurious from physical solution modes while maintaining accuracy and strict energy conservation.