Thermal Radiation, Convection, and Conduction in Porous Media Contained in Two-Dimensional Vertical Cavities

Abstract

This publication deals with the modeling of heat transfer by thermal radiation and natural convection in a fluid-saturated semitransparent porous medium contained within a inclinable two-dimensional cavity whose larger boundaries are isothermal and gray, whereas the small boundaries are insulated and reflecting. Applications are mainly relevant to the thermal insulation technologies, due to the wide use of high-porosity insulation in many engineering systems. The model used here is entirely two-dimensional and is based on the P1 approximation for the treatment of thermal radiation in an isotropically scattering semitransparent medium. Such a model is necessary when dealing with small-aspect-ratio cavities or when the convective heat transfer is less important than the radiative transfer.