Three-dimensional analysis of heat transfer and entropy production of jet impingement hybrid nanofluid cooling a porous media-filled heat sink

In this study, a numerical assessment was carried out on heat transfer and entropy production of a three-dimensional heat sink exposed to an impinging jet, where the area between the heat sink fins is filled with aluminum foam saturated with AL2O3−Cu/water hybrid nanofluid. Darcy-Brinkman-Forchheimer's model with the local thermal equilibrium was considered. The effects of various important parameters such as Reynolds number 400≤Re≤1600, volumetric concentrations 1%≤φhnf≤5%, Darcy number 10−5≤Da≤10−1, porosity 0.1≤ε≤0.6, and the diameter of nanoparticles 20nm≤dn≤60nm on fluid flow, heat transfer, drop pressure, and entropy generation were investigated. A finite-volume approach with SIMPLE algorithm was employed to solve continuity, momentum, energy, and entropy equations with the help of the Ansys-Fluent 14.5 program. Regarding the validation of the computational approach used in this paper, a strong consensus has been reached with other findings available in the literature. Outcomes indicated that boosting Darcy number Da and porosity ε of the used porous material helps increase the heat exchange rate by up to 72% and 40%, respectively. On the other hand, we obtained a 7% enhancement in the heat transmission rate when using nanoparticles with a diameter dn of 20nm instead of nanoparticles with a diameter of 60 nm. Furthermore, it has been demonstrated that boosting Da, ε and dn minimize drop pressure by various proportions. Based on the entropy production analysis, it is possible to infer that entropy due to heat transfer is more dominant than other types of entropy with all parameters analyzed. Also, it can be deducted that as the values of ε and Da grow and the values of dn decline, the total entropy production (Sp,t) rises up to 55%, 75% and 3%, respectively. The same findings were reached with the Bejan number Be, but different percentages. Finally, three correlations of Nusselt number with several variables with an error not exceeding 15% have been suggested. The proposed study's findings may be utilized to define appropriate process factors for improved thermodynamic efficiency of heat sinks using hybrid nanofluids and porous media.