Wake structure and sediment deposition behind models of submerged vegetation with and without flexible leaves
Wake structure and sediment deposition behind models of submerged vegetation with and without flexible leaves
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有和没有柔性叶子的水下植被模型背后的尾流结构和沉积物沉积
DOI：
10.1016/j.advwatres.2018.06.001
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发表时间：
2018-08
影响因子：
4.7
通讯作者：
Nepf Heidi
中科院分区：
文献类型：
--
作者：
Hu Zhenghong;Lei Jiarui;Liu Chao;Nepf Heidi
这项实验室研究探索了水下植被斑块直接下游的流动结构和沉积模式，重点关注柔性尾随叶片的存在是否增强了沉积。考虑了不同长度的叶子和不同几何形状（圆形和通道跨越）的斑块。该研究定义了尾流的长度，在该长度内，速度减小而净沉积增加。模型沉积物代表比细沙更小的有机或矿物固体。对于跨通道、浸没斑块、x-z（流向垂直）平面中的再循环或湍流扩散，设置尾流长度，在该尾流长度内速度减小且沉积增强。对于茎密度较低的斑块来说，这个长度更大，因为通过斑块的流量更大，将再循环涡流转移到下游更远的地方。此外，对于跨越通道的斑块，柔性尾叶的存在延长了尾流长度，这反过来又增加了沉积区域的长度。相反，对于圆形斑块，尾流包含 x-y（流向 - 横向）平面中的振荡。尾流不稳定的开始决定了沉积区域的长度。由于圆形斑块上柔性尾叶的存在不会影响尾流振荡的形成距离，因此随着柔性尾叶的添加，沉积区域的长度没有变化。对于圆形和跨通道斑块，较长的沉积区域与较大的沉积质量相关。
This laboratory study explored the flow structure and pattern of deposition directly downstream of submerged patches of vegetation, focusing on whether, or not, the presence of flexible trailing leaves enhanced deposition. Both leaves of different length and patches of different geometry (circular and channel-spanning) were considered. The study defined the length of wake within which the velocity was diminished and net deposition was enhanced. The model sediment represented an organic or mineral solid smaller than fine sand. For a channel-spanning, submerged patch, recirculation or turbulent diffusion in thex-z(streamwise-vertical) plane set the wake length within which velocity was diminished and deposition was enhanced. This length was greater for patches with lower stem densities, because greater flow through the patch displaced the recirculating eddy farther downstream. In addition, for a channel-spanning patch, the presence of flexible trailing leaves extended the wake length, which in turn increased the length of the deposition region. In contrast, for a circular patch, the wake contained oscillations in thex-y(streamwise – lateral) plane. The onset of the wake unsteadiness set the length of the deposition region. Because the presence of flexible trailing leaves on a circular patch did not affect the formation distance for the wake oscillation, the length of the deposition region was unchanged with the addition of the flexible trailing leaves. For both circular and channel-spanning patches, a longer deposition region was associated with a larger deposition mass.
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DOI：
10.1002/2013jf002858
发表时间：
2013-12
期刊：
Journal of Geophysical Research: Earth Surface
影响因子：
--
作者：
A. Ortiz;A. Ashton;H. Nepf
通讯作者：
A. Ortiz;A. Ashton;H. Nepf
影响因子：
5.4
作者：
Chen, Zhengbing;Ortiz, Alejandra;Nepf, Heidi
通讯作者：
Nepf, Heidi
DOI：
10.1017/cbo9780511806049.003
发表时间：
1995-01
期刊：
--
影响因子：
--
作者：
P. Julien
通讯作者：
P. Julien
影响因子：
3.7
作者：
S. Taddei;Costantino Manes;B. Ganapathisubramani
通讯作者：
S. Taddei;Costantino Manes;B. Ganapathisubramani
DOI：
10.1016/0167-6105(81)90010-6
发表时间：
1981-01-01
影响因子：
4.8
作者：
PERERA, MDAES
通讯作者：
PERERA, MDAES