Comparative study of WSGG and SLW models coupled with control volume finite element method for non gray radiation prediction

Abstract

For gray radiative heat transfer, the control volume finite element method (CVFEM) has received a significant attention owing to its flexibility and compromise between accuracy and computational requirements. The main goal of this paper is to evaluate the accuracy and the computational efficiency of the CVFEM coupled with the weighted sum of gray gases model (WSGGM) and the spectral line-based weighted sum of gray gases model (SLWM) in solving non gray radiative heat transfer. A numerical code was developed and its predictive accuracy was evaluated by applying it to 2-D enclosure containing a single participating gas (CO2 or H2O) at uniform temperature and a non isothermal mixture of gases.Computed radiative heat fluxes proved that i) CVFEM-SLWM and CVFEM-WSGGM solutions are in acceptable agreement with those of the RTM-SNBM which is considered the most accurate method, ii) combined with SLWM, the CVFEM gives very accurate results compared to the CVFEM-WSGGM but with more CPU time, iii) the CVFEM-WSGGM is better than the DOM-WSGGM and iv) with CVFEM-SLWM and CVFEM-WSGGM a reduction by 60% in the number of nodes and by 90% in the number of directions can be obtained compared to the DOM-SLWM and the DOM-WSGGM while maintaining a satisfactory precision.