An efficient cellular flow model for cohesive particle flocculation in turbulence
An efficient cellular flow model for cohesive particle flocculation in turbulence
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DOI：
10.1017/jfm.2020.79
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发表时间：
2020-01
影响因子：
3.7
通讯作者：
Kunpeng Zhao;B. Vowinckel;T. Hsu;T. Köllner;B. Bai;E. Meiburg
中科院分区：
文献类型：
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作者：
Kunpeng Zhao;B. Vowinckel;T. Hsu;T. Köllner;B. Bai;E. Meiburg
我们提出了一个单向耦合模型，跟踪单个初级粒子在一个概念上简单的细胞流设置来预测絮凝湍流。这种计算效率高的模型占斯托克斯阻力，润滑，凝聚力和直接接触力的主要球形颗粒，并允许一个系统的模拟活动，产生的瞬态平均絮凝物的大小作为一个功能的管理无量纲参数。模拟再现增长的粘性絮体随着时间的推移，和出现的对数正态平衡分布所管辖的聚集和破碎的平衡。当一次粒子的Stokes数为O（1）时，絮凝作用进行得最快。从这个简单的计算模型的结果与实验观察是一致的，从而使我们能够提出一个新的分析絮凝模型，产生改进的协议与实验数据，特别是在瞬态阶段。
We propose a one-way coupled model that tracks individual primary particles in a conceptually simple cellular flow set-up to predict flocculation in turbulence. This computationally efficient model accounts for Stokes drag, lubrication, cohesive and direct contact forces on the primary spherical particles, and allows for a systematic simulation campaign that yields the transient mean floc size as a function of the governing dimensionless parameters. The simulations reproduce the growth of the cohesive flocs with time, and the emergence of a log-normal equilibrium distribution governed by the balance of aggregation and breakage. Flocculation proceeds most rapidly when the Stokes number of the primary particles is $O(1)$. Results from this simple computational model are consistent with experimental observations, thus allowing us to propose a new analytical flocculation model that yields improved agreement with experimental data, especially during the transient stages.