水流作用下的悬沙垂向扩散系数

Vertical diffusion coefficient of suspended sediment in flows

利用华东师范大学河口海岸学国家重点实验室的波-流-泥沙变坡水槽,进行系列二维均匀流平衡输沙情况下悬沙扩散特性研究实验。根据实验数据,计算不同水流情况下的悬沙浓度垂向分布,确定悬沙垂向扩散系数及它的垂向分布。所得结果表明悬沙垂向扩散系数与水流扩散系数成正比,其比例系数正比例于摩阻流速;悬沙扩散系数的垂向分布可用抛物线来描述。

Experiments on sediment mixing characteristics by two-dimensional uniform currents were carried out by using wave-flow-sediment flume. From experimental data, the vertical distribution of suspended sediment concentration and vertical sediment diffusion coefficient in different flow conditions are determined. It is found from experimental results that the vertical sediment diffusion coefficients are proportional to vertical fluid diffusion coefficients and their ratio is related to the bed shear velocity. The vertical distribution of sediment diffusion coefficient may be described by parabola.