Experimental Study on Preparation and Physical Properties of Nanofluids

In this study, three nanofluids, CuO, SiC, and TiO2, are prepared by a two‐step method, and the factors affecting the stability, thermal conductivity, viscosity and density of the three are analyzed, so as to provide theoretical reference for strengthening heat transfer of the nanofluids. First, the effects of different dispersant addition amounts, magnetic stirring time, and ultrasonic oscillation time on the stability of nanofluids are analyzed in this paper, and finally chose the best solution for preparing three nanofluids. Second, the paper determines the thermal conductivity, viscosity, and density of three kinds of nanofluids and explores the factors affecting their physical properties. The thermal conductivity of the three nanofluids at the highest temperature is 2.9, 3.2, and 1.4 times that of the lowest temperature, respectively. When the temperature increased from 25 to 65 °C, the viscosity of CuO nanofluids decreases the most at different volume concentrations, and the viscosity decreases by 41.3% at 0.6% volume concentration. The density of nanofluids decreases with the increase of temperature and increases with the increase of volume concentration. At 25 °C, the density of SiC nanofluid increases the most with the volume concentration, and its density increases by 0.72%.