New experimental correlation for the thermal conductivity of ethylene glycol containing Al2O3-Cu hybrid nanoparticles

In the present study, the thermal conductivity of the Al2O3-Cu/EG has been experimentally investigated. For this purpose, a mixture of Al2O3 and Cu nanoparticles with a ratio of 50:50 was dispersed in ethylene glycol at different concentrations (0.125, 0.25, 0.5, 1.0, 1.5 and 2.0) and temperatures (25-50 degrees C). The two-step method is used for dispersing nanoparticles in the base fluid. Results show that the thermal conductivity of nanofluid is more than the base fluid, and it depends on volume concentration and temperature. Experimental results have been compared with some of the most famous models, and it has been found that these models are unable to predict the thermal conductivity of investigated nanofluid. Finally, based on the experimental data, a correlation is presented as a function of the temperature and volume fraction of nanoparticles.