Numerical Investigation of Second Law Efficiency using Nanofluids Coolant for Wavy Fin Automobile Radiator

Abstract

The field of Compact heat exchangers is gaining more and more attention, as for the
increased requirement of heat transfer rate. For the reason, there is an abundance of
research that is being carried out in the field of heat transfer for compact heat exchangers.
Now-a-days, compact heat exchangers are widely used with conventional coolants viz. water
and ethylene glycol, in many thermal and fluid systems. However, the conventional coolants
offer low thermal conductivity, and moreover the traditional techniques to increase the
cooling capacity of compact heat exchangers employing various fin geometries are becoming
obsolete. Hence, a new and innovative fluid for improving heat transfer rate via compact heat
exchangers is the need of the day. But, thanks to advancement in nanotechnology, for
developing new generation of heat transfer fluids known as ‘Nano-fluids’, which offer high
thermal conductivity as compared to conventional coolants.
This study is focused on the application of water based nano-fluids (Al2O3 and ZnO) in an
automotive cooling system, and compared their performance for wavy fin geometry with
considering the Effect of various operating parameters such as inlet mass flow rate of air,
inlet mass flow rate of coolant, inlet temperature of air and inlet temperature of coolant on
radiator for exergy analysis.
It was observed that Second law efficiency in the engine cooling system increased with the
usage of nano-fluids compared to water coolant only. It was also observed that, about 6 to
7% increment in the second law efficiency by using nano-fluids in wavy fin automobile heat
exchanger.