Abstract
Heat transfer enhancing method is more and more needed to decrease power consumption. This study was carried out to develop a high performance vortex generator, and find out the relationship between vortex structure and heat transfer. Double delta winglet pair was developed to reduce pressure drop with keeping up vortex strength. It was clarified that double delta winglet pair had higher performance than deltawinglet pair by 11% at flow velocity of 1.0m/s by measuring average heat transfer coefficient and pressure drop. It was found out that double delta winglet pair had the position of vortex core at short distance from heat transfer surface than delta winglet pair. Therefore, the heat transfer coefficient was larger than delta winglet pair's one, even though it's vortex strength was smaller than that.
