The effect of surface emissivity on three-dimensional conductive/radiative heat transfer in an absorbing/scattering medium is determined. The zonal method and the concept of total exchange factor (TEF) are used as a basis for the solution to the radiative transfer equation. The generalized zonal method combined with the Monte Carlo (GZM-MC) method is used to generate the TEF for a rectangular enclosure with a diffusely reflecting boundary. The solution approach is shown to be effective in generating numerically converged solutions that can serve as benchmark solutions to assess the accuracy of other radiation solvers. Numerical data are generated to demonstrate the significant effect of surface emissivity. The heat transfer from a hot bottom surface in a rectangular enclosure with diffusely reflecting boundaries is reduced by more than a factor of Formula: see text compared to the case with black boundaries. The corresponding temperature distributions also have significant differences. Qualitatively, the temperature in the region near the hot boundary is much higher for the case with diffusely reflecting boundaries. The difference in some local temperatures between the two cases can reach 50%.
Walter W. Yuen (Mon,) studied this question.