Compressible Coupled Natural Convection and Volumetric Radiation in a Square Cavity

International audienceCoupled thermal convection with radiation in the cavity containing a participating medium has been reexamined numerically in order to determine the conditions under which the Boussinesq approximation is applicable. It is part of this approximation that density variations appear solely in the buoyancy term of the momentum equation and are neglected in all other terms. The coupled momentum, energy, and radiative transfer equations are solved by an iterative procedure based on coupled discrete ordinates and finite volume methods in the context of low-Machnumber approximation of the Navier-Stokes equation. Based on the results of this study, it is found that, in the presence of the participating medium, the Boussinesq approximation is true for temperature differences approximately less than 120 K