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为研究恒定流和往复流饱和输沙情况下的泥沙扩散系数的规律,此文根据水沙两相紊流理论建立一个适用于全沙输移的二维数学模型,并利用物理模型试验的结果验证数学模型的正确性。研究表明,恒定流中水面处给定紊动动能为0的条件和给定紊动动能梯度为0的条件时,扩散系数的分布形式有很大的不同,但两种条件下浓度沿水深的分布没有明显的差别。往复流中泥沙扩散系数在水深方向上受浓度分布和往复流边界层内紊动特征的影响,呈现出一种十分复杂的时空变化规律。
In order to study the regularity of sediment diffusion coefficient under the conditions of constant flow and reciprocating flow saturated sediment transport, a two-dimensional mathematical model suitable for the transport of the whole sand was established according to the theory of water and sediment two-phase turbulence. Based on the physical model test The results verify the correctness of the mathematical model. The results show that there are great differences in the distribution of diffusion coefficient when the given turbulent kinetic energy is zero at the surface of a constant flow and when a given turbulent kinetic energy gradient is 0. However, There is no obvious difference in distribution. The sediment diffusion coefficient in the reciprocating flow is affected by the concentration distribution in the depth direction and the turbulent characteristics in the boundary layer of the reciprocating flow, showing a very complex temporal and spatial variation law.