Water-surface oscillations in channels with axi-symmetric cavities
Water-surface oscillations in channels with axi-symmetric cavities
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DOI：
10.1080/00221686.2010.534671
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发表时间：
2011-02
影响因子：
2.3
通讯作者：
T. Meile;J. Boillat;A. Schleiss
中科院分区：
文献类型：
--
作者：
T. Meile;J. Boillat;A. Schleiss
沿着空腔、河堤、沙场或港口的水流可以观察到水体的横向或纵向运动。它们对某些流动条件和几何特性具有重要意义。为了研究大尺度粗糙度对河岸的影响，在实验室水槽中，在亚临界湍流自由表面流动条件下，研究了36种轴对称矩形空腔的几何形状。检测到水体有明显的运动。这些周期性运动的频率，由水平和速度观测确定，与假设一阶晃动模式的矩形盆地中水体的固有频率一致。通过排除0.42和0.84附近的Strouhal数，可以避免水体的重大运动导致水面的显著和周期性振荡。对于低宽向空腔比，如果水流重新附着在加宽河段的侧壁上，则水面周期性振荡不显著。
Transverse or longitudinal movements of a water body are observed for flows along cavities, river embayments, groyne fields or harbours. They are significant for certain flow conditions and geometrical properties. To study the effect of large-scale roughness on banks, 36 geometries of axi-symmetric, rectangular cavities were investigated in a laboratory flume under subcritical, turbulent free surface flow conditions. Significant movements of the water body were detected. The frequency of these periodic movements, identified by level and velocity observations, is in agreement with the natural frequency of the water body in a rectangular basin assuming the first-order mode of sloshing. Major movements of the water body, which lead to significant and periodic oscillations of the water surface, are avoided by excluding Strouhal numbers near 0.42 and 0.84. For low aspect cavity ratios, the periodic water-surface oscillations are insignificant if the flow reattaches to the sidewalls of the widened channel reach.