The Effective Thermal Conductivity of Water Based Nanofluids at Different Temperatures

摘要

Three types of Al_2O_3/water, CuO/water, and TiO_2/water nanofluids were prepared by dispersing nanoparticles in water. A surfactant (cetyltrimethylammonium bromide (CTAB)) was used to improve the dispersion of nanoparticles and suppress the formation of particle clusters to obtain stable suspensions. The effective thermal conductivity was measured using a thermal property analyzer. The addition of a surfactant did not have any effect on the thermal conductivity. The effect of nanoparticle particle concentration (0.3, 0.6,1,1.5, and 2 wt. %) at four nanofluid temperatures (40, 45, 50, and 60℃) was investigated. Results indicated that the thermal conductivity increased with increases in particle concentration and temperature. Two models (linear and nonlinear) were developed to predict the thermal conductivity.