Abstract
Two numerical methods for solving the radiative heat transfer in a gradient index semitransparent slab are compared. The slab is discretized into many sublayers. The constant refractive index assumption in a sublayer and the ray splitting and tracing technique are used in the first method, and the linear approximation of refractive index in a sublayer and the curved ray tracing technique are adopted in the second method. The heat transfer at radiative equilibrium and coupled radiation-conduction are involved in the comparison. The results of the two methods show good agreement, but their calculating efficiencies are found to be quite different.