An Experimental and Numerical Analysis of Natural Convection in Open Square Enclosure

Experimental and numerical study of natural convection of air in a partially open square enclosure with two internal heat sources, located at the respective centers of the bottom wall and the right vertical wall, are performed. The left vertical wall, made up of an aluminum plate, has a partial opening that occupies 12.8%, 25%, and 50% of the wall. The effect of opening sizes and Rayleigh numbers on natural convective heat transfer is evaluated. The temperature distribution and the average Nusselt numbers at various Rayleigh numbers are obtained experimentally using the Mach-Zehnder interferometer. These results are compared with the temperature distribution obtained from a numerical simulation performed using ANSYS Fluent 2020 and a maximum deviation of below 8% is obtained with respect to the average Nusselt number. The fringe patterns are found to be highly clustered at higher Rayleigh numbers and larger opening sizes. The average Nusselt number is observed to be higher at higher Rayleigh number and larger opening. The primary circulating cell is stronger for 50% opening which leads to higher heat transfer.