The Fins Effect on Radiation-Convection Phenomenon Inside a Square Cavity Filled with Nanofluid

Abstract

This work presents numerical modelling of natural convection and radiation coupling in a square enclosure with stiff walls packed with a nanofluid. A radiation flux has been applied to the left wall ( Φ rad ) while the right wall is maintained at a cold temperature ( T c ). The studied configuration is equipped with fins. The fins are deemed perfectly conductive, with varying lengths and positioned on several cavity walls. The finite difference method solves the dimensionless governing equations system. The UPWIND scheme is used to solve the convective terms. The study concentrated on the influence of radiative flux and fins addition on convective behavior. Results proved that rising the intensity of the radiative flux leads to an intensification of the convective heat transfer phenomenon. By growing the radiation flux from 400 to 450 W/m 2 , the average Nusselt number increases by 119.19% and 63.47% when the fin is connected to the hot (case 1) and cold side (case 2), respectively, for Ra 10 6 and Φ = 8%. In addition, increasing the Ra number from 10 4 to 10 6 for a maximum radiation flux and Φ = 8% causes 1954.12% and 209% enhancement of the heat transfer rate for case 1 and case 2, respectively. Similarly, it is found that adding a fin on the hot side causes a reduction of 78.45% in the heat transfer rate, unlike the addition of a fin on the cold wall, which causes an augmentation of 14.67% compared to the case without a fin, for Φ = 0% and Φ rad = 450 W/m 2 .