An optimization study of heat transfer enhancement due to jet impingement over porous heat sinks using the lattice boltzmann method

In this paper, an optimization study involving five variable parameters that are critical in evaluating the thermal performance of the air jet flow impingement over porous heat sinks in a mixed convection regime is presented. The variable parameters include the porous block height, channel height, jet width, porosity, and Darcy number. The lattice Boltzmann method for porous media is used as the numerical tool to simulate the objective functions in terms of the Nusselt number and pressure drop. The Kriging method combined with a genetic algorithm is used to generate the optimal Pareto plot. Three optimal cases from the Pareto plot showing the maximum, minimum, and optimum Nusselt numbers and the pressure drop are considered. The optimized results show that the porosity and Darcy number are relatively invariant along the Pareto surface. Thus, the geometry of the channel and porous block are the most significant parameters governing the Nusselt number and pressure drop values. The results from optimization corresponding to the three optimal cases are analyzed in detail. The local variation in the Nusselt number for these cases is also plotted to understand the effect of the channel and porous heat sink parameters on heat transfer.