The Effective Thermal Conductivity of Water Based Nanofluids at Different Temperatures

Three types of Al2O3/water, CuO/water, and TiO2/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 degrees C) 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.