Enhancing heat transfer in a plate-fin heat sink using delta winglet vortex generators

Abstract

In this study, both experiments and simulations are performed to investigate the thermal-fluid characteristics of a flat-fin heat sink with a pair of vortex generators installed in a cross flow channel. The effects of the distance between the trailing edges of the vortex generators, the distance between each vortex generator and the heat sink, the attack angle of the vortex generators, the height of the vortex generators, the configuration of the vortex generators, and the Reynolds number on the thermal-fluid performance of the plate-fin heat sink are elucidated. The performance of the heat sink with the vortex generators was compared to that without.The results thus obtained revealed that when the distance between the trailing edges of the vortex generators is too small, the thermal performance becomes worse because the air cannot easily flow into the heat sink. Regarding the effect of the position of the vortex generators on thermal performance, the best performance is achieve when the distance between the vortex generator trailing edges equals the length of the heat sink and the distance between the trailing edge of each vortex generator and the front end of the heat sink is zero. An attack angle of the vortex generators of 30° is preferred to optimize the thermal resistance and pressure difference. Although heat transfer increases with the height of the vortex generators, the pressure difference also increases. Regarding the effect of the configuration of the vortex generators on the performance of the heat sink, a common-flow-up configuration outperforms a common-flow-down configuration. The enhancement of the heat transfer of the heat sink by the use of vortex generators is greater, and the increase of the pressure difference is lower, at lower Reynolds numbers.