Abstract
In this paper, a particle imaging velocimetry (PIV) system of high-temporal-spatial resolution is used to investigate the spanwise vortex distribution of fully developed turbulent flows in an open channel and its relationship with the turbulence. The distributions of the time-averaged velocity, the turbulence intensity and the Reynolds stress are obtained in the longitudinal profile. The third-generation vortex identification method (based on the Omega-Liutex vector) is applied to accurately identify and analyze the vortex in the spanwise direction. The results suggest that the vortex density increases with the Reynolds number at a given aspect ratio (B / H) of the flow. The distribution trend of the spanwise vortex density in the vertical direction remains unchanged for different discharges. Specifically, the vortex density increases along the vertical direction and reaches the peak at y / H = 0.15, then decreases and reaches the bottoms at the flow surface.
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Acknowledgement
This work was accomplished by using the code Omega-Liutex UTA which was released by Chaoqun Liu at the University of Texas at Arlington.
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Project supported by the Major Program of the National Natural Science Foundation of China (Grant No. 51527809), the Research Project of China Three Gorges Corporation (Grant No. 0704106).
Biography
Bin Li (1995-), Male, Master
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Li, B., Yang, Wj., Li, J. et al. Analysis of the spanwise vortex of open channel flows based on the Omega-Liutex vortex identification method. J Hydrodyn 34, 148–155 (2022). https://doi.org/10.1007/s42241-022-0015-6
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DOI: https://doi.org/10.1007/s42241-022-0015-6