Single-Phase Thermal Transport of Nanofluids in a Minichannel

Abstract

As a promising candidate for heat transfer fluids in advanced cooling technologies, nanofluids have been studied extensively in the past decade. Despite the tremendous research efforts, it is still unclear if and how the presence of dispersed nanoparticles alters the thermal transport and leads to enhanced thermal performance of nanofluids. An experimental investigation was conducted to explore the single-phase forced convection of Al2O3-water nanofluids in a circular minichannel with 1.09 mm inner diameter. The Reynolds number studied ranges from approximately 600 to 2300. The friction factor and convective heat transfer coefficient were measured for nanofluids with volume concentrations of up to 2%. The effects of nanoparticle concentration and flow rate on the local and average heat transfer coefficient as well as Nusselt number are examined. It was found that, once the thermophysical properties of the nanofluids are properly accounted for, the established pressure drop and heat transfer correlations can offer satisfactory predictions of the single-phase thermal transport of nanofluids under the experimental conditions considered in this study.