Radiation transfer in participating medium interacting with variable property natural convection subjected to collimated/diffused irradiation at boundary—A critical appraisal

The current study addresses the interaction phenomenon of combined natural convection with radiation in the presence of radiatively active gray medium inside a two‐dimensional enclosure. The left wall is radiatively considered to be semitransparent and is subjected to collimated irradiation. All gray walls of the enclosure are assumed to diffuse, except the semitransparent wall which is considered to be specular in nature. Investigation is done for the flow which is considered to be steady, laminar, and two‐dimensional. The variation of properties (k, ρ, μ) with temperature has been taken into consideration to make the investigation realistic. The radiation modeling has been done with the higher order discrete ordinate radiation method (DOM). The finite volume discretization has been adopted for numerical simulation. The effect of varying properties has been delineated and its due consideration while modeling has been realized. The results are depicted through isotherm and streamline patterns. The effects of influencing parameters on the Nusselt number have also been illustrated. A critical appraisal is made examining the suitability of the radiation models starting from S₄ to S₃₂, for different situations. © 2011 Wiley Periodicals, Inc. Heat Trans Asian Res; Published online in Wiley Online Library ( wileyonlinelibrary.com/journal/htj ). DOI 10.1002/htj.20403