Computational Fluid Dynamics-Based Analysis of Entropy Generation on Laminar Natural Convection in Enclosures With Partitioned Walls and for Different Heating Positions

Abstract

Abstract A numerical investigation is performed to analyze air's steady natural convection phenomena in an enclosure with partial active sidewalls. A partition is attached to the hot wall for different active locations to study the effect of the partition position on the heat transfer. First, a finite volume method solves the coupled equations of continuity, momentum, and energy. The SIMPLE algorithm is used to solve the pressure velocities coupling iteratively. Second, based on the obtained dimensionless velocity and temperature values, the distributions of the local entropy generation due to heat transfer and fluid friction and the total entropy generation are determined for different parameters. The results are presented graphically in streamlines, isotherms, and average Nusselt numbers. Three different configurations of active region arrangement are considered in this study, while the partition length has been changed. In order to identify the optimum location of the partition for better heat transfer, the effect of entropy generation has been studied. The heat transfer rate decreases with the increased partition length, especially for l = L/2. Thus, the maximum average Nusselt number occurs for the middle–middle arrangement, while the minimum one occurs for the bottom–bottom arrangement. The numerical investigations in this analysis are made over a wide range of parameters, Rayleigh number 103 to 105, dimensionless partitions length (l = L/8, L/4, L/2), and irreversibility coefficients 10−4< ϕ < 10−2; however, the Prandtl numbers was fixed to 0.71.