The pattern of surface waves in a shallow free surface flow
The pattern of surface waves in a shallow free surface flow
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DOI：
10.1002/jgrf.20117
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发表时间：
2013-09-01
影响因子：
3.9
通讯作者：
Maximov, G. A.
中科院分区：
文献类型：
--
作者：
Horoshenkov, K. V.;Nichols, A.;Maximov, G. A.
这项工作提出了新的水面高程数据，包括在浅水流动产生的水面波的空间相关性的证据在砾石床没有明显的床的形式。仔细的实验室实验表明，这些水面波不是众所周知的重力波或毛细波，而是由不同的物理现象引起的。在所研究的流动条件下，存在于浅流中的剪切产生流动结构，其上升并冲击水-空气界面。结果表明，这些水面波的空间相关函数可以近似为W（rho）= e（-rho 2/2 sigma w2）COS（2 π L-0（-1）rho）。所提出的近似取决于空间相关半径，sigma（w），特征空间周期，L-0，和空间滞后。这种近似适用于本研究中检查的所有水力条件。它示出，L-0涉及到的深度平均流速，并进行信息的垂直速度剖面和床面粗糙度的形状。研究还表明，σ（w）与水力粗糙度和水流雷诺数有关。
This work presents new water surface elevation data including evidence of the spatial correlation of water surface waves generated in shallow water flows over a gravel bed without appreciable bed forms. Careful laboratory experiments have shown that these water surface waves are not well-known gravity or capillary waves but are caused by a different physical phenomenon. In the flow conditions studied, the shear present in shallow flows generates flow structures, which rise and impact on the water-air interface. It is shown that the spatial correlation function observed for these water surface waves can be approximated by the following analytical expression W(rho) = e(-rho 2/2 sigma w2)COS(2 pi L-0(-1)rho). The proposed approximation depends on the spatial correlation radius, sigma(w), characteristic spatial period, L-0, and spatial lag, . This approximation holds for all the hydraulic conditions examined in this study. It is shown that L-0 relates to the depth-averaged flow velocity and carries information on the shape of the vertical velocity profile and bed roughness. It is also shown that sigma(w) is related to the hydraulic roughness and the flow Reynolds number.