Abstract
A staggered distribution of vegetation is very common in nature, which might significantly affect the flow structure. To investigate its impact, three rows of staggered vegetation groups are designed under seven different working conditions. The horizontal and vertical distances between the vegetation groups are constant, while the vegetation density is variable. The flow field is measured by the acoustic Doppler velocimeter (ADV). It is indicated that both the patch exit velocity and the steady wake velocity decrease with the increase of the density, which is also related to the vegetation rows. Except for the first patch, the upstream adjustment regions of all patches are diminished to some extent, due to the effect of the contralateral patch. The steady wake region also shows a decreasing trend, with a reduction of 0.5D each time when the water flows through the patch. This means that the flow structure is also affected by the number of vegetation rows. The intensity of the turbulence increases along the channel and has a non-axisymmetric distribution similar to that of the velocity. The Karman vortex street generated by the patches on the same side would merge into a larger vortex street. Depending on its intensity, the vegetation at the back has different effects on the vortex street.
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Projects supported by the National Natural Science Foundation of China (Grant Nos. 51979181, 51539007).
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Hong-sheng Fu (1995-), Male, Ph. D., E-mail: 18392889719@163.com
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Fu, Hs., Wang, D., Li, Wq. et al. Velocity and turbulence characteristics in an open channel with multi-row staggered vegetation patches. J Hydrodyn 33, 1035–1044 (2021). https://doi.org/10.1007/s42241-021-0091-z
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DOI: https://doi.org/10.1007/s42241-021-0091-z