Thermal Radiation Effects on the Laminar Free Convection Boundary Layer of an Absorbing Gas

The effects of thermal radiation upon the laminar free convection boundary layer of a vertical flat plate were studied for absorbing and nonabsorbing gases. Experimental velocity and temperature profiles were obtained for a constant heat flux boundary condition in air and CO2 and these are compared to analytical calculations for optically thin gases and absorbing gray gases. A correlation is presented by which plate surface temperatures as a function of plate emissivity for optically thin gases may be predicted for use in determining the convective heat transfer through standard non-radiative film heat transfer correlations.