Effect of nanofluids on heat transfer and pressure drop characteristics of diverging-converging minichannel heat sink

Abstract

Combine effects of nanofluid and variable cross-section minichannel heat sink has become a remarkable option for efficient cooling of thermal devices like miniature electronic devices and compact heat exchangers. In this paper, the single-phase numerical method was employed to study the effect of different nanofluids on heat transfer and pressure drop penalty in the Diverging-converging minichannel heat sink (DCMCHS). CFD analysis carried out using commercial ANSYS software employing the finite volume method. The nanofluids are prepared as stable nanoparticles of Al 2O3, Cu, and SiO2 and suspended in deionized water with concentrations of 0-0.8% volume. The DCMCHS subjected to a uniform heat flux of 45000 W/m2 and the fluid flow within the transition’s region with Reynolds number 2000 to 2300. The validations of numerical data conducted with results from empirical correlations exhibit a good agreement with about 9% deviation. The results revealed an insignificant change in pressure drops with a variation of nanofluids loadings, whereas, the increase in Reynolds number and nanoparticle loading indicated a considerable influence on the enhancement of heat transfer coefficient. Al 2O3–water nanofluid shows better performance in terms of heat transfer than other nanofluids. The results indicate that nanofluid and DCMC can enhance the hydro-thermal performance of the heat sink.