Performance of discretely mounted metal foam heat sinks in a channel with nanofluid

Abstract

Solving the heating problem of electronic systems, whose performance and power consumption increase with the developing technology, has been the common research topic of many researchers today. In this context, conventional cooling methods should be improved by using innovative materials to achieve more effective cooling performance. In this study, metal foam heat sinks (Al-6101) with pore densities of 10 and 40 pore per inch were utilized instead of commercially finned surfaces used in electronic cooling applications, and their effects on thermal and pressure performance were investigated. The experiments were carried out under steady state conditions. As the coolants, the deionized water (base fluid) and CuO-H2O nanofluids which was prepared with different concentrations and surfactant additive, were used. The volumetric flow rates of the fluids were chosen in range of 17.6 L/h − 76.5 L/h and the heat fluxes were selected in range of 3267 W/m2 − 5400 W/m2. The effect of each parameter on heat transfer was investigated with 5 different prepared nanofluids. The following experiments were carried out by using metal foam heat sinks and the nanofluid (w/w, 0.1% CuO/2% PEI-H2O) where the best results were obtained. The obtained results were compared with the base fluid. With the use of 10 and 40 pore per inch metal foam heat sinks together with the base fluid, an improvement in the mean convection heat transfer coefficient between 11.1% and 22.2% was achieved at all heat fluxes and volumetric flow rates compared to the empty surface (surface without metal foams). When nanofluid (w/w, 0.1% CuO/2% PEI-H2O) was used together with metal foam heat sinks, an improvement changing between 26.3% and 42.5% was recorded. When the effect of all parameters used in the experiment were examined, the best results in terms of thermal performance were obtained when nanofluid with w/w, 0.1% CuO/2% PEI-H2O content and 10 pore per inch metal foam heat sinks were used together. Results suggest that the use of nanofluid together with metal foam will satisfy the economy and power consumption requirements of cooling electronic systems.