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

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. [Display omitted] •A novel carbon based hybrid nanofluid was prepared by non-covalent functionalization method.•Hybrid nanofluid comprises of GnP and MWCNT nanoparticles in 1:1 ratio, which was dispersed in radiator coolant (base fluid).•An aluminium finned automobile radiator is fabricated for experimentation.•A comprehensive experimentation on the thermal performance of an engine radiator was performed using the hybrid nanofluid.•The maximum improvement in OHTC was found as ∼ 124% at 0.5 vol %, 5 m/s air velocity, when compared with the base fluid.