Electro-Thermal Simulations with Skin-Layers and Contacts

We show a coupled electro-thermal simulation of a large, complex industrial device that yields a steady state temperature distribution with only small deviations from measurements. Firstly, the Ohmic losses in the conductors are calculated by a FEM-solver for the time-harmonic full Maxwell equations. To this end, we introduce a model to account for electric contact resistances, and a gradient based error indicator for adaptive mesh refinement. Secondly, the steady state temperature distribution is computed by a commercial CFD solver, taking into account convective and radiative cooling to balance the Ohmic heating. Theoretical arguments and simulation results hint that good predictions of total Ohmic losses and temperature distributions can be obtained on comparably coarse meshes which do not fully resolve the skin layer.