On the calculation of suspended load for noncohesive sediments
On the calculation of suspended load for noncohesive sediments
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DOI：
10.1029/91jc02933
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发表时间：
1992-04
影响因子：
--
通讯作者：
S. Mclean
中科院分区：
文献类型：
--
作者：
S. Mclean
悬浮泥沙输移率的计算需要在水流深度上对泥沙浓度乘以流速的乘积进行积分;因此，特别是在沉积床附近，需要这些量的精确剖面。虽然这看起来是一项简单的任务，但许多影响可能导致这些量与简单已知关系所预期的值发生重大偏差。例如，悬浮颗粒的密度分层可以抑制湍流波动，并显著降低流动的有效粘度和扩散率。本文求解了动量方程和悬移质方程，包括悬移质分层的影响以及粒度分布和底形的影响。结果表明，分层和底形一般减少流量的运输能力，而处理的沉积物作为一个集合的不同大小，而不是一个单一的大小（D50）增加了预期的运输。
Calculation of suspended sediment transport rates requires integration of the product of sediment concentration times velocity over the depth of the flow; hence accurate profiles of these quantities are required especially near the sediment bed. Although this would appear to be a straightforward task, many effects can cause significant deviation of these quantities from those values expected from simple known relationships. For example, density stratification by suspended particulates can dampen turbulence fluctuations and significantly reduce the effective viscosity and diffusivity of the flow. The momentum and suspended sediment equations are solved herein, including the effects of stratification by suspended sediment and the effects due to size distribution and bedforms. The results show that stratification and bedforms generally reduce the transport capacity of the flow, whereas treating the sediment as an assemblage of different sizes rather than a single size (D50) increases the expected transport.