Numerical solution of radiative transfer within a cubic enclosure filled with nongray gases using the WSGGM

Abstract

Using a weighted sum of gray gases model with gray gas regrouping technique (WSGGM-RG), problems of radiative transfer within three-dimensional enclosures filled with non-homogeneous and non-isothermal combustion gas mixtures were solved. The radiative transfer equation was solved based on discrete ordinate method (DOM) and raytracing method (RTM) with WSGGM-RG. The results using WSGGM-RG were compared with those using the statistical narrow band (SNB) model. The average radiative intensities and radiative heat fluxes using WSGGM-RG corresponded relatively well to those using the SNB model as reference data. A very good computational efficiency was also noted.

Influence of the gray gases number in the weighted sum of gray gases model on the radiative heat exchange calculation inside pulverized coal-fired furnaces

“…The average and maximal relative errors generally decreased with the increase in the number of regrouped gray gases, and when the number of gray gases was bigger than five, the reduction of the average and maximal relative errors became unimportant. Results presented by Coelho [10] and Park and Kim [12] showed that the difference in radiative heat transfer calculations in 3-D enclosures with fixed temperature and concentration distributions decreased with increases in the number of gray gases.…”

“…With some exceptions, an increase in the number of gray gases from 3 to 20 decreased the average and maximal relative errors. Park and Kim [12] used the regrouping technique to investigate the possibility of reducing the number of gray gases of the narrow band based WSGM. The exact values of the wall fluxes and average intensity of radiation inside the cubic 3-D enclosure with fixed temperature and concentration spatial distribution were found using the statistical narrow band model.…”