Effect of Low Volume Concentration on Heat Transfer Enhancement of EG-Water Based Fe3O4 Nanofluid

Abstract

Customization of thermophysical properties of the working fluids has tremendous potential in heat transfer enhancement. In the present paper, experimentation is conducted to determine the heat transfer coefficient and friction factor of 20:80 Ethylene Glycol-Water(20:80 EG-Water) based Fe3O4 nanofluid in a Double Pipe Heat Exchanger with U Bend (DPHE). Experiments are performed in the turbulent flow regime at an operating temperature of 47.5°C. Fe3O4 nanoparticles of size less than 50 nm are mixed with 20:80 EG-Water solution in the volume concentration range of 0.02% to 0.08%. Results indicate that as the concentration of nanoparticles increase, the heat transfer coefficient of the nanofluid increases up to 0.04% concentration and then decreases, while the friction factor is observed to increase with the increase of volume concentration. Within the Reynolds number range considered in the analysis, the average enhancement in the heat transfer coefficient is 24.1% at 0.04% concentration compared to that of the base fluid. The average enhancement in the friction factor is observed to be 25.58% at 0.08% concentration of Fe3O4/ 20:80 EG-Water nanofluid compared to that of base fluid.