Coupling heat conduction and radiative transfer

A method to compute combined heat conduction and radiative transfer in a semitransparent medium is proposed. The heat equation is solved by an implicit finite-difference scheme and the radiation is simulated using a ray-tracing method. Stability and convergence for the coupling of both methods is shown. The crucial point for ray-tracing as well as for discrete-ordinate methods is the selection of the transfer directions and their associated weights. Using a model problem different direction sets proposed in the literature are compared with respect to their accuracy and the computational effort.