Numerical study of natural convection in square tilted solar cavity considering extended domain

Abstract

This work presents a numerical investigation on heat transfer and fluid-dynamic aspects for a solar open cavities in an extended fluid flow domain. The vertical wall inside the open cavities facing the aperture is assumed to be isothermal while the other walls are kept insulated. Heat transfer steady laminar natural convection is studied by solving the non-dimensional governing equations of mass, momentum and energy in the framework of a finite volume method. The analysis are carried out under Rayleigh number range of 9.41×10 5 to 3.76×10 6 , inclination 0° to 90° and opening ratio 0.25, 0.5 and 1. The model results for avaergar Nusselt number evaluation was in good agreement with other published work for similar configuration. The results show that convective average Nusselt number decreases by 93% when the inclination angle increased from 0° to 90° due to the trapped vortices that limit the airflow throughout the cavity. The air flowing through the cavit is maximum when the the inclination angle is zero even at higher values of Raylight number. Results show also that decreasing the opening ratio from 1 to 0.25 leads to a drop in heat loss by 22.79%. A simple correlation has been developed for calculating the the average Nusselt number as a function of Rayleigh number, opening ratio and inclination angle.