Characterization of physical properties of nanofluids for heat transfer application

Water based nanofluids of SiO₂ and Al₂O₃ were characterized regarding its later use in heat transfer applications. Well dispersed nanofluids were prepared at three different volume fractions (0.5% v., 1% v., 5% v.) and for each one the experimental measurements were carried out at three different temperatures (40°C, 60°C, 80°C). Commercial nanofluids acquired in liquid state were compared with nanofluids prepared by dispersing dry powder in water. The thermal conductivity, the viscosity and the specific heat of all the prepared nanofluids were measured in order to calculate the Mouromtseff number and establish the optimal conditions. Finally, the stability of the nanofluids was also studied through the evolution of the amount of light scattered by the sample during a period of time.