Flow Characteristics in the Wake Region of a Finite-Length Vegetation Patch in a Partly Vegetated Channel
Flow Characteristics in the Wake Region of a Finite-Length Vegetation Patch in a Partly Vegetated Channel
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DOI：
10.3390/w10040459
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发表时间：
2018-04
期刊：
影响因子：
3.4
通讯作者：
D. Yılmazer;A. Y. Ozan;K. Cihan
中科院分区：
文献类型：
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作者：
D. Yılmazer;A. Y. Ozan;K. Cihan
河流和沿海地区的水生植被通过平均流速和湍流来控制水流结构。水流中的植被影响营养物质、微生物、溶解氧、沉积物和污染物的传输，因此，为了了解植被对水流结构的影响，需要研究不同类型植被层的水流特性。本文研究了横跨半条航道的植被斑块的淹没比和固体体积分数对尾流区流动结构的影响。为此，实验中考虑了不同的淹没比和不同的SVF，并使用声学多普勒测速仪(ADV)在植被层尾流区进行了速度测量。根据计算结果，得到了不同植被高度和不同SVF对流速分布的影响。此外，还得到了植被层尾流区断面上的弯曲速度分布，得出了由于植被层的存在，在航道的非植被部分出现了急流。
Aquatic vegetation in rivers and coastal regions controls the flow structure in terms of mean velocity and turbulence. The vegetation in the flow affects the transportation of nutrients, microbes, dissolved oxygen, sediment, and contaminants; therefore, the flow characteristics of different types of vegetation layers should be examined in order to understand the effects of vegetation on the flow structure. In this paper, the effect of the submergence ratio and SVF (Solid Volume of Fraction) of a vegetation patch, which was present across half of the channel in a spanwise direction, on the flow structure at the wake region was examined. For this purpose, different submergence ratios with different SVFs were considered in the experiments, and velocity measurements were performed in the wake region of the vegetation layer with an Acoustic Doppler Velocimeter (ADV). According to the results, the effect of different vegetation heights and SVFs on the velocity distribution was obtained. Moreover, inflectional velocity distribution over the cross-section in the wake region of the vegetation layer was obtained, and it was concluded that jet flow occurred in the non-vegetated half of the channel due to the vegetation layer.