Heat and mass transfer of combined forced convection and thermal radiation within a channel: Entropy generation analysis

Abstract

The present paper deals with a numerical modelling of thermal and mass transfer coupled by thermal radiation and forced convection in a semi-transparent medium during the evaporation of a thin water film used for wall protection within a channel. Particular attention is paid to the analysis of the entropy generation due to heat transfer and mass diffusion. The governing equations are solved numerically using the Finite Volume Method. Furthermore, the resolution of the Radiative Transfer Equation was carried out by the “Ray-Tracing” method according to a symmetric quadratic scheme of SN (S4) whereas the radiative properties of the non-grey gas were deduced by the application of the “Statistical Narrow Band Correlated-K” (SNB-CK) model. The effect of several parameters on entropy generation due to conduction, thermal radiation and mass diffusion are analysed in this paper. The results clearly demonstrate the major dominance of the wall radiative entropy generation in all the studied cases. The results also prove that for high values of drywall temperature and emissivity, the entropy generation due to mass diffusion augmented.