Development of new correlations for convective heat transfer and friction factor in turbulent regime for nanofluids

This paper presents new correlations for the convective heat transfer and the friction factor developed from the experiments of nanoparticles comprised of aluminum oxide, copper oxide and silicon dioxide dispersed in 60% ethylene glycol and 40% water by mass. The experimental measurements were carried out in the fully developed turbulent regime for the aforementioned three different nanofluids at various particle volumetric concentrations. First, the rheological and the thermophysical properties such as viscosity, density, specific heat and thermal conductivity were measured at different temperatures for varying particle volume concentrations. Next, these properties were used to develop the heat transfer coefficient correlation from experiments, as a function of these properties and the particle volumetric concentration. The pressure loss was also measured and a new correlation was developed to represent the friction factor for nanofluids. (C) 2010 Elsevier Ltd. All rights reserved.