Experimental investigation of an automobile radiator using carbon based hybrid nano coolant

Abstract

Comprehensive experimentation on the heat transfer performance of a vehicle radiator with a novel hybrid nanofluid (HyNf) comprising Graphene nanoplatelets (GnP) and Multi-walled carbon nanotubes (MWCNT) nanoparticles in 1:1 ratio, dispersed in radiator coolant oil (base fluid), has been performed. Non-covalent functionalization method was implemented to prepare steady nanofluids for volume concentrations of 0.05%, 0.1%, 0.15%, 0.2%, 0.3%, 0.4%, and 0.5%. Tests were conducted for different nanofluid flow rates from 20 g/s to 100 g/s in 5 steps, three different nanofluid entry temperatures of 30 °C, 50 °C and 70 °C and three different air velocities viz. 1, 3 and 5 m/s. The enhancement in thermal conductivity (TC) was observed as 59% for 0.5 vol % compared to base fluid, which leads to an augmentation in the convective heat transfer coefficient (CHTC) of nanofluid. The maximum improvement in overall heat transfer coefficient (OHTC) was found as ∼ 124% at 0.5% volume concentration, 5 m/s air velocity, compared to the base fluid. A rise in the pressure drop is found as 23.72% compared to base fluid. Due to these enhanced heat transfer behaviours of the synthesized GnP-MWCNT/coolant oil HyNf, it can be an alternate to the existing coolant oil.