Effective influence distance of longitudinal vortex in narrow rectangular channel

With relative long influence distance and simple structure, the longitudinal vortex generators (LVGs) can be used in narrow channels with flat surface in order to enhance heat transfer. The influence distance of longitudinal vortex (LV) is very important to extend this kind of technology in narrow rectangular channel with water as the working fluid. In this paper, this problem is numerically studied and based on the residual rate of vortex intensity, the effective influence distance of LV is 68.3~77.4 times of LVG height, which is independent on the Reynolds numbers.