LES of Mixed Convection Boundary Layer Between Radiating Parallel Plates

Abstract The inuence of natural convection on a mixed convection boundary layer in a vertical channel is studied using Large-eddy simulation. A constant heat ux bound-ary condition is applied to one of the channel walls while the other wall is insulated. The Grashof and Reynolds numbers based on the wall heat ux and the channel width are Gr = 9:4 107 and Re = 5080. As the temperature difference between the hot wall and the inlet air is large, the governing equations are solved using two different approaches namely Boussinesq approximation considering constant properties and the equations with variable properties. As a consequence of hot wall high temperature, radiation is also taken into ac-count and it is shown that about 10 % of the heat is transferred via radiation. Although variable property equations yield better solutions compared to the constant property equa-tions, there exist substantial differences between the computed and the measured proles which might be due to the numerical scheme that has impaired the imposed turbulence at the inlet. 1