COMBINED NATURAL CONVECTION AND SURFACE RADIATION IN A SQUARE CAVITY WITH THE INVERSELY LINEARLY HEATED OPPOSITE SIDE WALLS

This paper presents the results of numerical analysis of coupled laminar natural convection and surface radiation in a two-dimensional closed square cavity with the inversely linearly heated vertical opposite side walls and the adiabatic top and bottom walls. The cavity is filled with natural air (Pr = 0.70) as the fluid medium. In the present study, the governing equations i.e., Navier-Stokes Equation in the stream function - vorticity form and Energy Equation are solved for a constant property fluid under the Boussinesq approximation. For discretization of these equations, the finite volume technique is used. For the radiation calculations, the radiosity-irradiation formulation is used and the shape factors are calculated using the Hottel's crossed-string method. The effects of pertinent parameters like Rayleigh Number (10(3) <= Ra 10(6)) and the surface emissivity of walls (0.05 <= epsilon <= 0.85) are studied and analyzed.