Numerical investigation of effect of the flow field structure and cooling medium of tubes on the heat transfer performance of automotive radiator

Abstract

The flow field structure and cooling medium of tubes have major influence on the heat transfer performance of automotive radiator. In this study, two novel types of radiator tube (wasp-waisted tube 2# and wasp-waisted tube 3#) are developed, six types radiator tubes with different flow field structures and equal flow cross-sectional area are numerically simulated. In addition, four nanofluids with different concentrations (Al2O3-water, SiO2-water, TiO2-water, and CuO-water) were studied in Reynolds number 2500-7500. The results show that the heat transfer capacity of the wasp-waisted tube 2# and the wasp-waisted tube 3# is significantly better than that of the other radiator tubes, followed by the wasp-waisted tube. Compared with the wasp-waisted tube, the heat transfer coefficient of the wasp-waisted tube 2# and the wasp-waisted tube 3# increased by 10.6% and 3.5%, respectively. On the other hand, nanoparticles improve the heat transfer efficiency of base fluid. When Reynolds number reaches 7500 and the volume concentration is 3%, the Nunf/Nubf of SiO2-water is 5.52%, 5.22%, and 8.70% higher than that of Al2O3-water, TiO2-water, and CuO-water, respectively. The comprehensive heat transfer capacity of SiO2-water-3% in the wasp-waisted tube is the best.