Experimental investigation on viscosity of AlN and SiC nanofluids

Abstract

The quest for effective and efficient heat exchange systems has been a subject of recent research. Nanofluids are high performance ultra-modern heat transfer fluids with superior properties compared to those of regular heat transfer fluids. Therefore, studies on the viscosity of nanofluids are essential owing to its effect on the pumping requirements of thermal systems. This article investigates the influence of concentration and temperature on the dynamic viscosity of AlN and SiC nanofluids. Nanofluids with a volume concentration of 0.5–5% were prepared by dispersing AlN nanoparticles in ethylene glycol (EG), SiC in ethylene glycol, and SiC in distilled water (DW) using the two-step method. The experimental investigation on the viscosity of these nanofluids was performed at the temperature range of 28–60 °C using an Ostwald viscometer. It was observed that the measured nanofluids exhibited an increase in the viscosity with an increase in the volume concentration of nanoparticles. Specifically, for SiC/DW nanofluids at 0.5 and 5% volume concentration, the viscosity ratio was 1.023 and 1.435 times that of the base fluid. Moreover, the viscosity of nanofluids is reduced by increasing the temperature relative to that of their base fluids. The experimental values were compared with existing theoretical model, and their predictions are below the experimental results; therefore, correlation was derived on the basis of the experimental data. The margin of deviation of these models in predicting the viscosity of the studied nanofluids varied between −15 and 23% for AlN/EG; −7 and 21% for SiC/EG, and −11 and 4% for SiC/DW nanofluid.