Numerical study of coupled heat transfers through hollow structures exposed to a solar flux

Abstract

Abstract This work examines numerically, the heat transfer coupled by conduction, natural convection and radiation through hollow block subjected to real boundary conditions. A hollow block of this type is usually used for the construction of ceilings in buildings. The top horizontal face of this hollow block is exposed to an solar irradiance and exchange heat with the air ambient with a thermal transfer coefficient. While the lower face exchange heat with the indoor air with another thermal transfer coefficient. And an adiabatic vertical side is assumed. The discretization of partial differential equations governing and boundary conditions was done using the finite differences method and the SIMPLE algorithm. The effects of the solar irradiance and the emissivity of the internal cavity surfaces on the flow structures were examined. The results showed that the emissivity affect the heat transfer through the hollow block considerably. The solar flux alters significantly the flow structure and the thermal fields through the studied structure.