Time-Domain Surface Impedance Boundary Conditions Enhanced by Coarse Volume Finite-Element Discretisation

The time-domain surface impedance boundary conditions allow to accurately account for the high-frequency flux components while removing the massive conducting regions from the computation domain. In this paper, a coarse volume finite-element discretization of the conductors together with a fictitious frequency-dependent conductivity are added to capture the slow varying flux components. This hybrid approach extends thus the frequency range of these impedance conditions. A 2-D test case illustrates the method.