Numerical analysis on thermal and hydraulic performance of diverging-converging minichannel heat sink using Al2O3-H2O nanofluid

Abstract

Miniaturization as a size reduction of electronic devices components lead to high performance, but with increase in heat flux density which reduce the efficiency of these devices. Minichannel has been considered to improve the heat dissipation with minimal pressure drop through regulation of the channel configurations. In this study, a divergent-convergent minichannel heat sink (DCMCHS) was investigated numerically using Finite volume method to model single-phase forced convection for nanofluid cooling as a passive means to enhance the heat transfer performance for Reynolds number range of 2000 to 2300 and using Aqueous Alumina as nanofluid with concentrations of 0.1 – 0.8%. The effect of Reynolds number, the convection coefficient and pressure drop in relation to the heat flux were investigated and discussed. The results show that, Nusselt number increases with increase in volume fraction and Reynolds number, whereas friction factor decreased with increasing Reynolds number. Heat removal by the nanofluid is higher near the walls than in the central part of the minichannel, and the performance factor is between 1.00 – 1.01 and it increases with increase in concentration and flow velocity. Thus, combine passive techniques of DCMCHS and nanofluid provides better enhancement of heat transfer and hydraulic attributes of the minichannel heat sink for cooling purposes.