ANALYTICAL INVESTIGATION OF FORCED CONVECTION HEAT TRANSFER IN A FLAT-PLATE SOLAR COLLECTOR FILLED WITH A POROUS MEDIUM BY CONSIDERING RADIATION EFFECT

Abstract

In the present study, heat transfer in a thin flat-plate solar collector with a fully saturated porous channel is investigated analytically by considering convection-radiation heat transfer. The fluid flow has been modeled by the Brinkman-Forchheimer extended Darcy model. The heat transfer equation has been solved analytically based on the perturbation method. The temperature profile and Nusselt number have been extracted and then the collector thermal performance has been analyzed for the first time. The results show that, although the radiation and porous shape parameters have considerable effects on the Nusselt number and collector thermal performance, the effect of radiation is more noteworthy than the porous shape parameter. The Nusselt number increases up to two times with an increase in the radiation parameter. In order to establish a balance between the pressure drop increase and heat transfer improvement due to porous matrix, these parameters were evaluated simultaneously. It is observed that the change in the flow pressure drop is negligible in small values of porous shape parameter.