Abstract
Accurate radiative heat transfer analysis is challenging due to the strongly spectral-dependent absorption coefficient and the requirement for satisfying both the summation and reciprocity laws in thermodynamics. In the paper, nongray radiation is treated by way of a computationally efficient Weighted Sum of Gray Gases (WSGG) model without much sacrificing prediction accuracy. In the present model, three gray gas components are used, one of which simulates the radiative window. The thermodynamic laws are simultaneously treated using a Monte Carlo method subject to a symmetrization procedure. As a test problem, radiative heat transfer in an industrial model furnace is solved to demonstrate effects of gray/nongray radiation and the grid size for CFD and radiation calculations.