Contemporary trends in thermo-hydraulic testing and modeling of automotive radiators deploying nano-coolants and aerodynamically efficient air-side fins

摘要

Automotive radiators cool the engine coolant preventing heat seizure due to thermal expansion. Since both the coolant pump and radiator fan are parasitic devices (power has to be supplied by the engine), radiators with lower air-side and coolant pressure drop deploying coolants with superior thermo-physical characteristics that consume lower engine power need to be designed. Hence, augmented radiators with better overall heat transfer enhancement using improved tube-side and air-side geometries that emit fewer emissions, save energy and can be easily fabricated, tested and analysed are necessary. This review addresses this issue. Specially designed and fabricated air-side fins and flat extruded coolant tubes have significantly improved the thermal performance of engine cooling systems. This article reviews the state-of-the-art in experimental testing and computational modeling of enhanced radiators which can be deployed with high performance vehicles and their superiority over conventional radiators. Unlike other reviews which focused solely on coolant tube and air-side design and spacing, flow velocities and pressure drops, this article will also focus on the impact of nano-coolants on improving the thermal efficiency of radiators while summarizing the efficacy of aerodynamically efficient air side fins like delta-winglets in reducing air-side pressure drop. This article aims to consolidate the available literature in the 21st century (experimental and analytical) for enhanced radiators equipped with unconventional coolants and aerodynamically designed air-side fins and should serve as a single reference for practicing engineers and graduate students.