Probability Density Function of Instantaneous Drag Forces and Shear Stresses on a Bed
Probability Density Function of Instantaneous Drag Forces and Shear Stresses on a Bed
复制标题
床上瞬时阻力和剪应力的概率密度函数
DOI：
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发表时间：
2006
期刊：
影响因子：
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通讯作者：
J. A. Battjes
中科院分区：
文献类型：
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作者：
B. Hofland;J. A. Battjes
本文导出了紊流中床面瞬时切应力的概率密度函数。有人认为，PDF的形状是类似的PDF的瞬时拖曳力的床糙率元素。PDF中包含了近床相对湍流强度的影响。分布的形状比较好，与我们的测量的瞬时阻力的一个突出的床元素的湍流强度的范围。然而，在高湍流强度下，偏差是明显的。PDF也与光滑壁面上的剪应力测量值进行了比较。
A probability density function (PDF) of the instantaneous bed shear stress in a turbulent flow is derived in this paper. It is argued that the shape of the PDF is similar to the PDF of the instantaneous drag forces on bed roughness elements. The influence of the near-bed relative turbulence intensity is included in the PDF. The shape of the distribution compares well with our measurements of the instantaneous drag force on a protruding bed element for a range of turbulence intensities. However, deviations are apparent at high turbulence intensities. The PDF also compares well with measurements of shear stresses on a smooth wall.