Use of an optically thin boundary-layer model in calculations of radiative heat-exchange processes

The possibility is considered of using an approximation of an optically thin boundary layer in computations of radiative heat-exchange processes. Nusselt numbers obtained for an optically thin layer and for layers of various optical thicknesses are compared. The effect of the governing parameters of the problem on the magnitude of dispersion is clarified, and the range in which the optically thin model yields satisfactory results is indicated. It is noted that this model yields the most satisfactory results in problems involving gases with a small absorption coefficient.