Author(s): Qi E-Rong; Li Guo-Ya; Li Wei; Wu Jian; And Zhang Xin
Linked Author(s):
Keywords: Flow around a circular cylinder; Vortex structure; PIV
Abstract: In the gap-ratio range of 0. 0 ≤ G ≤ 0. 7 (i. e. from the point when a circular cylinder touches the bottom wall to the point when the circular cylinder touches the water surface), a particle image velocimetry (PIV) is applied to conduct a systematic experimental research of the flow around a horizontal circular cylinder in the cross-flow of shallow water. The velocity distribution of transient flow field at various gap-ratios is obtained. Based on these data, the phenomena and rules of the vortex and its course of generation, development and evolvement at various gap-ratios are analyzed, and it is found that there are similar unshedding vortex structures at G = 0. 0 and G = 7. 0, and others are structures of shedding vortex. The figures of typical vortex movements are given. Based on this, the differences between the transient flow field and the time-averaged flow field and the characteristics of the vortex structures are analyzed. The findings of this paper are of guiding significance for engineering issues with similar flowing features.
Year: 2005