Abstract
The effect of surface radiation on the developing laminar mixed-convection flow of a transparent gas between two asymmetrically heated vertical parallel plates is investigated. The effect of surface radiation on wall temperatures, fluid temperature profiles, location of the channel height at which the buoyancy forces balance the viscous forces, the location of the onset of pressure build up, the location of the onset of flow reversal, average friction factor, and Nusselt number are illustrated. The values of the emissivity at which surface radiation engenders minimum pumping power requirements are obtained. Finally, threshold values of the surface emissivity at which radiation effects can be neglected are presented. (C) 2012 Elsevier Masson SAS. All rights reserved.