Abstract
Thermal conductivity of ethylene glycol and water mixture based Fe3O4 nanofluid has been investigated experimentally. Magnetic Fe3O4 nanoparticles were synthesized by chemical co-precipitation method and the nanofluids were prepared by dispersing nanoparticles into different base fluids like 20:80%, 40:60% and 60:40% by weight of the ethylene glycol and water mixture. Experiments were conducted in the temperature range from 20 degrees C to 60 degrees C and in the volume concentration range from 0.2% to 2.0%. Results indicate that the thermal conductivity increases with the increase of particle concentration and temperature. The thermal conductivity is enhanced by 46% at 2.0 vol.% of nanoparticles dispersed in 20:80% ethylene glycol and water mixture compared to other base fluids. The theoretical Hamilton-Crosser model failed to predict the thermal conductivity of the nanofluid with the effect of temperature. A new correlation is developed for the estimation of thermal conductivity of nanofluids based on the experimental data. (C) 2013 Elsevier Ltd. All rights reserved.