Combined free convection and surface radiation in tilted open cavity

A numerical investigation has been performed for steady, incompressible, laminar, free convection with surface radiation in a tilted 2D open cavity in which the wall facing the opening is heated by a constant heat flux source. The governing differential equations of mass, momentum and energy are solved using finite volume method. For surface radiation calculations, radiosity-irradiation formulation has been used, while the view factors required therein, are calculated using the Hottel's Crossed-string method. The effects of emissivity, tilt angle and Rayleigh number on the heat transfer in the tilted open cavity are analyzed. The results show that the heat transfer increases first and then decreases with decreasing the cavity tilt angle for all Rayleigh number and emissivity. Based on numerical data, correlations have been developed for average convective and radiative Nusselt numbers.