The Intensity of Secondary Flow in a Channel of Spiral Plate Heat Exchanger

In this paper the intensity of secondary flow in the channel of spiral plate heat exchanger is investigated using numerical method. Secondary flow in such channel is formed by Görtler vortices that are generated inside the spiral channel due to centrifugal force. The results show that Görtler vortices go three stages: generating, developing and decaying. The flow and geometric conditions affect the above mentioned stages. With the increase of Reynolds number Rem, the location of Görtler vortex starts to generate is advanced by some distance, the intensity of secondary evaluated by a no dimensional number Se increases by 2500 at the maximum, and the interference between vortex pairs is enhanced, and there is no Görtler vortex when Rem is less than 300. As the radius of inlet curvature Ri increases, the Görtler vortex generating position is delayed by some distance, and the intensity of secondary flow, Se, decreases by 750, the interference between vortex pairs is weakened. The width of the channel, b, and the height of the channel, h, basically do not affect the location where Görtler vortex generating in the spiral channel, but the different b and h have a certain effect on the interference of Görtler vortex and the intensity of secondary flow at the vortex decay stage.