Investigation on Heat Transfer Properties of Water Based TiO2-ZnO Nanofluids

Abstract

Nanofluids in heat transfer applications exhibit effective performance over conventional heat transfer fluids. High thermal loads due to miniaturization in a wide variety of applications offers technological challenges in designing efficient thermal management systems. Traditional heat transfer fluids such as air, water, engine oil, and ethylene glycol (EG) have very low thermal conductivities of 0.03, 0.613, 0.145 and 0.253 W/mK respectively. The poor thermal conductivity of these fluids is an obstacle in improving heat transfer and compactness of the heat exchangers. Determination of properties of nanofluids and its performance in water based base fluids has been studied by many researchers. However the heat transfer performance of mixed nanofluids ie., hybrid nanofluids is yet to be explored. TiO 2 and ZnO nanofluids were prepared at 0.5%, 1.5% and 2.0% volume concentration. Thermal conductivity estimated for temperature range of 30-70°C. Significant enhancement of both heat transfer rate and effectiveness of heat exchanger was noticed with TiO 2 nanofluids at 2.0% volume concentration and with 1.5% volume concentration of TiO 2 -ZnO hybrid nanofluids.