Experimental investigation of AL2O3-EG nanofluid thermal properties and heat exposure stability in closed circuit

Abstract

Paper presented at the 9th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Malta, 16-18 July, 2012.In the present study, we seek to further advance nanofluid research by simultaneously acquiring the thermal (thermal conductivity) and rheological (dynamic viscosity) properties of surfactant-free 80nm aluminium-oxide (alumina, Al2O3) spheroid gamma nanoparticle dispersions in 99.8% purity ethylene glycol (EG). Samples were diluted into 1, 2.5 and 5% by volume concentrations and pumped through an innovative purpose-developed thermally controlled closed system. Contrary to most studies which focus on individual property analysis through static burst (i.e. short term) data acquisition, concurrent data acquisition was achieved for relatively long testing periods, from 24 to 72 hours. This novel multifaceted approach also permitted to observe the long term effects of heat on colloid stability as well to insure repeatability of the data when applicable.