Combined natural convection enhancement in right-angled triangular cavities using helium and surface radiation

Abstract

Paper presented at the 7th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Turkey, 19-21 July, 2010.The present investigation deals with the numerical computation of laminar natural convection in upright-angled triangular cavities filled with helium. In each cavity, the vertical wall is heated and the inclined wall is cooled while the upper horizontal wall is thermally insulated from the ambient air. The defining aperture angle is located at the lower vertex between the vertical and inclined walls. To incorporate surface radiation, various levels of emissivities are assigned to the walls. The finite volume method is implemented to perforn the computational analysis encompassing three aperture angles ( 15", 30" and 45") in conjunction with height-based Rayleigh numbers ranging from a low 103 to a high 106. Numerical results for helium with and without surface radiation are reported for the buoyant velocity and temperature fields as well as the mean convective coefficient at the heated vertical wall.