Cohesive sediment: intermediate shear produces maximum aggregate size
Cohesive sediment: intermediate shear produces maximum aggregate size
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粘性沉积物：中间剪切产生最大骨料尺寸
DOI：
10.1017/jfm.2023.380
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发表时间：
2023
影响因子：
3.7
通讯作者：
Meiburg, E.
中科院分区：
文献类型：
--
作者：
Zhao, K.;Vowinckel, B.;Hsu, T.-J.;Bai, B.;Meiburg, E.
为了研究粘性泥沙在细尺度湍流中的凝聚与破碎平衡，我们采用Kolmogorov尺度和速度尺度对Taylor-Green涡胞模型进行了解释。单向耦合的数值模拟，捕捉凝聚力，润滑和直接接触力的絮凝过程中的影响，重现在以前的实验中观察到的平衡絮凝体的大小和剪切速率之间的非单调关系。单向耦合的结果证实了选择双向耦合模拟。中等剪切产生最大的絮凝体，因为它促进初级颗粒的优先浓缩，而不会产生足够强的湍流应力来破碎出现的聚集体。我们发现，最佳的中间剪切速率增加更强的凝聚力和更小的颗粒与流体的密度比，我们提出了一个简单的模型的平衡絮凝体的大小，符合文献中报道的实验数据。
We interpret the Taylor–Green cellular vortex model in terms of the Kolmogorov length and velocity scales, in order to study the balance between aggregation and breakup of cohesive sediment in fine-scale turbulence. One-way coupled numerical simulations, which capture the effects of cohesive, lubrication and direct contact forces on the flocculation process, reproduce the non-monotonic relationship between the equilibrium floc size and shear rate observed in previous experiments. The one-way coupled results are confirmed by select two-way coupled simulations. Intermediate shear gives rise to the largest flocs, as it promotes preferential concentration of the primary particles without generating sufficiently strong turbulent stresses to break up the emerging aggregates. We find that the optimal intermediate shear rate increases for stronger cohesion and smaller particle-to-fluid density ratios, and we propose a simple model for the equilibrium floc size that agrees well with experimental data reported in the literature.
影响因子：
3.7
作者：
Kunpeng Zhao;B. Vowinckel;T. Hsu;T. Köllner;B. Bai;E. Meiburg
通讯作者：
Kunpeng Zhao;B. Vowinckel;T. Hsu;T. Köllner;B. Bai;E. Meiburg
影响因子：
2.7
作者：
Chen, Sheng;Li, Shuiqing;Marshall, Jeffrey S.
通讯作者：
Marshall, Jeffrey S.