Optimal configuration and thermal performance of heated rectangular blocks under forced convection with volume constraints

Abstract

Papers presented to the 11th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, South Africa, 20-23 July 2015.This paper presents thermal management of heat transfer density rate from heated blocks mounted on a horizontal wall of a rectangular enclosure and subject to forced convection. The governing equations for mass, momentum and energy for laminar flow and convective heat transfer are solved in three-dimensions using a commercial Computational Fluids Dynamics (CFD) code. First numerical results validated with available experimental data showed that the rate of heat transfer increase with the Reynolds number. Thereafter a numerical optimization procedure is carried out in order to obtain the optimal blocks configuration that maximizes the heat transfer density rate and minimizes the peak temperature in the enclosure by selecting the sides of the blocks as design variables whilst the total volume is maintained constant. In term of the thermal performance of the heat transfer mechanism described by the dimensionless global conductance as well as by the overall Nusselt number, the results showed that optimal configurations were such that none of the blocks aspect ratio was equal to one. However thermal performance was much better when either the height-to-length ratio (B/G) or the heightto- width (B/C) ratio tends to its maximum. These optimal results obtained numerically are found to be fairly reliable.