Numerical investigation of the effects of fin shape, antifreeze and nanoparticles on the performance of compact finned-tube heat exchangers for automobile radiator

Highlights: • Louvered fin has the highest heat transfer rate compared to other fins. • Shape of VGs and their arrangement over the fin have considerable effects. • The orientation of VGs compared to each other is significant. • Adding antifreeze to water reduces radiator heat transfer rate. • Adding nanoparticles to radiator cooling fluid can be chosen as a passive solution. - Abstract: In this paper, heat transfer and pressure drop of air in the radiator of an internal combustion engine automobile were investigated. First, three types of fins including louvered, triangular vortex generator and rectangular vortex generator were modeled and their performance were compared with a plain fin. Effects of adding antifreeze in volume ratios of 40, 50 and 60% on the performance of louvered and rectangular vortex generator fins were investigated. Finally, the effects of adding copper oxide and aluminum oxide nanoparticles on the heat transfer improvement of louvered and rectangular vortex generator fins were simulated. The results demonstrated that louvered fin had the highest heat transfer rate compared to the other fins and improved it up to 24.6% in comparison with plain fin; however, its air side pressure drop increased 67.7%. Adding antifreeze resulted in a decrease in heat transfer rate. For example, heat transfer rate decreased for louvered and rectangular vortex generator fins at 60% vol. antifreeze, 12.9 and 11.8% compared to pure water, respectively. Also, adding copper oxide and aluminum oxide nanoparticles improved heat transfer rate and compensated harmful effects of antifreeze and it increased heat transfer rate in comparison with pure water.