The Role and Effects of Thermal Radiation on the Non-equilibrium Heat Transfer in a Porous Filled Enclosure

Abstract

Abstract In this paper, the temperature differential between the solid and liquid phases in considering of combined conduction-convection-radiation heat transfer in porous media is investigated. Simultaneous solution of the solid and fluid energy equations encompasses local thermal nonequilibrium, with volumetric radiative heat flux needed in the solid-phase energy equation. The two energy equations together with the radiative heat transfer equation are simultaneously solved using the Chebyshev spectral method. The influences of the Planck numbers, the optical thicknesses, the scattering albedos, and the emissivities of the bounding walls on the thermal behavior are investigated. The results show that: (1) When Pl increases above 20, the effect of radiation on the flow and thermal field can be ignored. (2) Changing ⌖L has a significant effect on the solid phase temperature while, the effect is little on the fluid phase temperature. (3) For ω = 1.0, the distribution of θS − θf seems to be centrally symmetric. (4) θS − θf are always positive except for εW = 1.0.