Heat Transfer Analysis in a Square Cavity: Effects of Nusselt, Reynolds, and Prandtl Numbers

Abstract

This work focuses on a theoretical and numerical and numerical study of the thermal behavior of certain physical parameters of air. The aim is to show the importance of natural convection in heat transfer, based on the contribution of parameters such as Nusselt, Prandt and Reynolds, which often influence heat transfer. These parameters in a thermal cavity show the extent to which an engineer can design a cooling system based on solar energy. The prototype studied and built is exposed to the sun's rays, and one of its sides is covered with a transparent pane to transmit heat by conduction inside the device. The trapped air creates a greenhouse effect, promoting heat exchange by convection. The study was carried out at the Carnot Energy Laboratory in Bangui (CAR). The equations governing the operation of the device presented in fluid mechanics in the case of conservation of mass, momentum and energy were written and solved numerically by the finite volume method, implemented in MATLAB. In order to take into account temperature-dependent density variations, so that the physical so that the physical properties of the fluid can be considered constant at low temperatures, the Boussinesq approximation is necessary for two-dimensional steady-state flow conditions. Numerical results for the distribution of different temperatures were presented, along with targeted correlations highlighting the influence of these thermal parameters. These results reveal the influence of the Nusselt number on heat transfer.