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 Al₂O₃, 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. Al₂O₃–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.