Effects of wave shape on sheet flow sediment transport
Effects of wave shape on sheet flow sediment transport
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DOI：
10.1029/2003jc002075
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发表时间：
2004-05
影响因子：
--
通讯作者：
T. Hsu;D. Hanes
中科院分区：
文献类型：
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作者：
T. Hsu;D. Hanes
[1]采用两相模型研究了片状流条件下波浪形态对粗粒泥沙输运的影响。该模型基于流体和沉积物相的平均质量、动量和波动能量的平衡方程。模型模拟结果表明，片流的响应，如速度剖面、瞬时床层剪应力、泥沙通量和动沙总量等，不能用准稳定的自由流速度完全参数化，而可能与局部水平压力梯度（或自由流加速度）的大小有关。在波浪推进方向上，对于典型的浅滩波和破碎波的弯曲波和锯齿波形态，均获得了净泥沙通量。该模型进一步表明，当水平压力梯度达到临界值时，河床内发生破坏事件，将更多泥沙动员到活动板中，从而增强泥沙通量。将总河床剪应力和总泥沙通量参数化的初步尝试看来是有希望的。
[1] A two-phase model is implemented to study the effects of wave shape on the transport of coarse-grained sediment in the sheet flow regime. The model is based on balance equations for the average mass, momentum, and fluctuation energy for both the fluid and sediment phases. Model simulations indicate that the responses of the sheet flow, such as the velocity profiles, the instantaneous bed shear stress, the sediment flux, and the total amount of the mobilized sediment, cannot be fully parameterized by quasi-steady free-stream velocity and may be correlated with the magnitude of local horizontal pressure gradient (or free-stream acceleration). A net sediment flux in the direction of wave advance is obtained for both skewed and saw-tooth wave shapes typical of shoaled and breaking waves. The model further suggests that at critical values of the horizontal pressure gradient, there is a failure event within the bed that mobilizes more sediment into the mobile sheet and enhances the sediment flux. Preliminary attempts to parameterize the total bed shear stress and the total sediment flux appear promising.