Comparison of global radiative models in two-dimensional enclosures at radiative equilibrium

Abstract

Radiative heat transfer in 2D rectangular enclosures filled with real participating gases is considered. Several global radiative property models, namely two gray gas models, the Full Spectrum k-distribution (FSK) model, the Spectral Line Based Weighted Sum of Gray Gases (SLW) model are assessed by comparison with reference calculations based on LBL approach. The angular and spatial discretization of the radiative transfer equation is performed using the discrete ordinates method and the finite volume method, respectively. Calculations are carried out for enclosures containing homogeneous/inhomogeneous mixtures of water vapor, carbon dioxide and nitrogen dioxide. Radiation is assumed to be the dominating mode of heat transfer and medium with prescribed temperature and at radiative equilibrium are considered. Accuracy and computational efficiency of these gas models were examined on six test cases. It is shown that for a medium at radiative equilibrium, all the models, except for Gray-Planck model, have good accuracy.