Performance improvement of wavy-plate heat exchanger by vortex generators with adjacent-reverse arrangement

Abstract

The installation of vortex generators on the heat transfer surface is an effective method for enhancing heat transfer. In this study, a novel arrangement of vortex generators with an adjacent-reverse arrangement on the bottom wall is investigated for wavy fin channel. Configurations of vortex generators with different attack angles are numerically compared. Moreover, the performance of the studied arrangement is compared with that of the normal arrangement in the literature. The results indicate that longitudinal vortices generated by vortex generators with an adjacent-reverse arrangement are more effective at disrupting fluid flow and, consequently, heat transfer improvement. The Nusslet number increases and then decreases with the increase in attack angles, with increments occurring every 15° from 15° to 75°. The Nusselt number of the studied wavy channel increases by 16.6 %–40.5 % for various attack angles compared with the smooth wavy channel, while the friction factor only increases by 7.5 %–30.3 %. Through coupled evaluation of heat transfer and pressure loss characteristics, the 60° attack angle demonstrates optimal performance, achieving a maximum thermal performance factor of 1.29. This value represents a 29 % enhancement compared with the smooth wavy channel. Furthermore, the studied configuration achieves a 5.1 % enhancement compared with the normal setup of vortex generators aligned in the same direction as found in the literature.