Numerical study of heat transfer enhancement by rectangular winglet vortex generator pair in a channel

Abstract

A numerical simulation was performed to investigate the effects of longitudinal vortices on the heat transfer enhancement of a laminar flow in a rectangle duct mounted with rectangular winglet pair on the bottom wall. The studied Reynolds number which was defined using the hydraulic diameter twice the channel height ranges from 500 to 7000. The comparisons of the fluid flow and heat transfer characteristics for the cases with and without rectangular winglet pair were carried out. The effects of the height and attack angle of vortex generator pair on the heat transfer performance were investigated. The results show that mounting rectangular winglet pair on the bottom wall of the channel can significantly enhance heat transfer. The distributions of secondary flow on the cross sections are consistent with the distributions of Nu and J for different attack angles. The maximum heat transfer performance is obtained when the attack angle is 29° due to the maximum value of secondary flow generated by rectangular winglet pair.