Thermal performance improvement of a heat-sink using metal foams for better energy storage systems

Abstract

Newly, energy storage systems and harvesting energy equipment are modern and important topics in engineering problems, but they still face the efficiency problem. Using the advantages of micro-scale flow and metal porous materials can be applied to improve the performance of these systems. So, the present investigation provides a numerical study on a heatsink employing various arrangements of metal foams inside a heat sink (in the direction and against the fluid flow). The influences of diverse fluid flow characteristics, metal foams' permeability and thermophysical properties of the coolant (using CuO-MgO/water nanofluids) on the thermal efficiency of the heatsink are examined. Then, the variations of convective heat transfer coefficient and pressure loss for all variables are investigated, and performance evaluation criteria are defined to distinguish the simultaneous impacts of improving heat exchange against incrementing the pressure loss. It indicates the metal foams located in the direction of the flow perform better than those located against the flow, which increases the performance evaluation criteria (PEC) of the heatsink between 1.18 and 1.55 depending upon the permeability of porous media. Also, using the nanofluids in the presence and absence of metal foams decreases the heatsink performance. Investigating the impacts of volumetric flow rate illustrates that thermal performance increases by increasing the flow rate. In addition, outcomes reveal that although adding metal foams and nano-additives and increasing volumetric flow rate enhance the frictional entropy generation rate, the total amount of entropy generation rate decreases due to more contribution of the thermal entropy generation rate, that reduces by those variables.