The effects of flocculation on the entrainment of fluid mud layer
The effects of flocculation on the entrainment of fluid mud layer
复制标题
絮凝对泥浆层夹带的影响
DOI：
10.1016/j.ecss.2020.106784
复制
发表时间：
2020-08
期刊：
影响因子：
--
通讯作者：
Yu Lili
中科院分区：
文献类型：
--
作者：
Xu Chunyang;Chen Yongping;Pan Yi;Yu Lili
絮凝是粘性泥沙输运过程的一个组成部分，因为它会进一步影响其他过程，如沉降，沉积以及侵蚀过程。为了解絮凝作用对不同盐度的浮泥卷吸过程的影响，进行了一系列的卷吸和沉降试验。在恒定水动力条件下，通过环形水槽顶部的剪切环驱动，进行了卷吸实验。在不同直径的圆柱体中进行了沉降实验。结果表明，不同盐度的浮泥在垂向上形成不同的含沙量分布，对浮泥的卷吸率有显著影响。高矿化度泥浆（E18）的携带速率小于低矿化度泥浆（E4）的携带速率。沉降试验表明，高矿化度的泥浆样品沉降速度加快，在较低的含沙量下达到胶凝浓度。这两种机理导致了不同絮凝状态下的浮泥含沙量分布不同。因此，泥浆特性，如密度、粘度、屈服强度、浮力效应和最终夹带率随不同的流体泥浆样品而变化（初始沉积物浓度相同）。并尝试用已有的方程预测雾沫夹带速率。计算结果与实验结果吻合较好，进一步说明在计算挟沙率时应考虑絮凝过程，因为要准确预测浮泥挟沙率，需要了解浮泥在垂向上的含沙量和流变特性。
Flocculation is an integral part for cohesive sediment transport processes as it will further influence other processes such as settling, deposition as well as erosion processes. To understand the impacts of flocculation on entrainment process of fluid mud with different salinities, a series of entrainment and sedimentation experiments were conducted. Entrainment experiments were conducted under constant hydrodynamic conditions driven by a shear ring on the top of an annular flume. While the sedimentation experiments were conducted within cylinders with different diameters. Results show that fluid mud samples with different salinities can form different distributions of sediment concentration in the vertical direction, which will significantly influence the entrainment rate of fluid mud. Results also show that entrainment rate of fluid mud with higher salinity (E18) is smaller than that of fluid mud with lower salinity (E4) in the upper layer of fluid mud. Sedimentation tests show that the settling rate of fluid mud sample with higher salinity is enhanced and the gelling concentration is reached at a lower sediment concentration. These two mechanisms cause the different distributions of sediment concentration for fluid mud under different flocculation states. Accordingly, the mud characteristics such as density, viscosity, yield strength, buoyancy effects and eventually the entrainment rate vary with different fluid mud samples (the initial sediment concentrations are the same). An effort has also been made to predict the entrainment rate with existing equation. The good agreement between from equation and experimental results further demonstrates that the flocculation process should be considered when calculating the entrainment rate, as accurate prediction of the entrainment rate of fluid mud requires the details of sediment concentration and rheological properties of fluid mud in the vertical direction.
登录
查看更多内容
闽江口悬浮颗粒物分布及絮凝观测
影响因子：
2.9
作者：
Dongyi Li;Yunhai Li;Yonghang Xu
通讯作者：
Yonghang Xu
影响因子：
3.6
作者：
DYER, KR
通讯作者：
DYER, KR
影响因子：
2.4
作者：
C. Kranenburg;J. Winterwerp
通讯作者：
C. Kranenburg;J. Winterwerp
DOI：
10.1680/hmime.01541.0009
发表时间：
1982
期刊：
--
影响因子：
--
作者：
M. Thorn
通讯作者：
M. Thorn
DOI：
10.1016/s0278-4343(01)00011-5
发表时间：
2001-10
期刊：
--
影响因子：
--
作者：
R. V. D. Ham;J. Winterwerp
通讯作者：
R. V. D. Ham;J. Winterwerp