Heat Transfer and Pressure Drop of Al2O3-Ethylene Glycol-water Nanofluid as the Coolant in an Automotive Radiator

In this experimental study, heat transfer and pressure drop, ΔP, of a coolant nanofluid, obtained by adding alumina nanoparticles to Ethylene Glycol-water mixture (60:40 by mass), in a automotive radiator have been investigated. For this purpose, an experimental setup has been designed and constructed. The experiments have been performed for base fluid and nanofluid with different volume fractions of 0.003, 0.006, 0.009 and 0.012 and under laminar regime with various coolant flow rates of 9, 11 and 13 lit/min and two air velocities of 3.75 and 2.85 m/s. The thermophysical properties have been calculated using the recently presented temperature dependent models. According to the results, the heat transfer and ΔP increase with increasing the coolant flow and nanoparticles volume fraction. Increasing the air velocity causes enhancement of heat transfer. Although Nusselt number decreases when nanofluid is utilized, it enhances as the nanoparticles volume fraction increases. The performance evaluation using nanofluid in the car radiator shows remarkable enhancement in radiator thermal efficiency. However, the ratio of heat transfer rate to the needed pumping power (Merit parameter) decreases.