Experimental and Theoretical Investigations of the Thermal Conductivity of Erbium Oxide/Ethylene Glycol Nanofluids for Thermal Energy Applications

Abstract The thermal conductivity of Er 2 O 3 /ethylene glycol (EG) nanofluids was investigated at different concentrations of Er 2 O 3 nanoparticles in the temperature range of 20–50 °C. The findings showed that the volume fraction of Er 2 O 3 nanoparticles and temperature affect the thermal conductivity. The thermal conductivity increases with increasing Er 2 O 3 concentration and temperature, and the Er 2 O 3 /EG nanofluid showed higher thermal conductivity than the base fluid. Precise correlations are proposed to forecast the thermal conductivity of the Er 2 O 3 /EG nanofluid relative to the base fluid. These results are promising for using Er 2 O 3 /EG nanofluid in solar thermal applications.