Effect of Rayleigh Numbers on Natural Convection and Heat Transfer with Thermal Radiation in a Cavity Partially Filled with Porous Medium

Abstract

In this paper, the effects of Rayleigh numbers on natural convection and heat transfer with thermal radiation in a cavity partially filled with a porous medium have been studied numerically. The governing equations for the momentum and heat transfer in both free fluid and porous medium were solved by the finite element method. The radiative heat transfer is calculated by making use of the radiosity of the surfaces that assumed to be grey. Comparisons with experimental and numerical results in the literature have been carried out. Effects of Rayleigh number on natural convection and heat transfer in both free fluid and porous medium were analyzed. It was found that Rayleigh numbers can significantly change the temperature fields in both the regions of free flow and porous medium. The mean temperature at the interface decreases and the temperature gradients are created on the upper two corners of the porous medium region as Ra increases.