LAUSR

Abstract In this work, hydrodynamics and heat transfer of alumina–water nanofluid in a microchannel heat sink (MCHS) are simulated and discussed. Attention in focused to analyze how the use of nanofluids as well as vertical/horizontal porous substrates on the channel walls may alter performance of the system, compared to other design variables. To this aim, a three–dimensional solid–fluid conjugate model in conjunction with the two–phase mixture model for the nanofluid and the Dacry–Brinkman–Forchheimer model for the porous medium is utilized. Sensitivity analysis of design variables is performed using the Taguchi method and analysis of variance (ANOVA). The mean temperature of the CPU surface, the overall thermal resistance, the required pumping power, and the figure of merit are considered as the performance parameters. An L27 orthogonal array is utilized as the experimental plan for the current design variables including thickness of the vertical/horizontal porous substrates, material of the MCHS and the porous substrates, the inlet velocity, and the nanoparticles fraction. It is found that the highest contribution on the mean temperature of the CPU surface, the overall thermal resistance, and the figure of merit belongs to the material of the MCHS and the porous substrates.