Critical sinking of hydrophobic micron particles
Critical sinking of hydrophobic micron particles
复制标题
疏水微米颗粒的临界沉降
DOI：
10.1016/j.ces.2019.06.009
复制
发表时间：
2019-11-02
影响因子：
4.7
通讯作者：
Yao, Qiang
中科院分区：
文献类型：
--
作者：
Ji, Bingqiang;Song, Qiang;Yao, Qiang
在自然和工业过程中经常观察到颗粒撞击液体表面。本研究以数值模拟的方式探讨疏水性微米粒子撞击液体表面后的临界下沉行为。分析了接触角θ、密度比D和雷诺数Re对颗粒和TPCL运动的影响。粒子的无量纲穿透深度随θ和D的增加而增加，而Re的影响可以忽略不计。颗粒上的TPCL位置与归一化颗粒位移之间的关系仅由θ确定，并且几乎不受Re和D的影响。对于疏水微米颗粒的临界沉降，流体力和表面张力在颗粒动能转换中起着重要作用。建立了一个无量纲的能量守恒方程，并在此基础上提出了一个简单的临界下沉准则。该准则的表达式是基于描述从模拟结果获得的每个无量纲累积功与Re、θ和D的关系的半经验表达式获得的。与现有准则相比，该准则合理地考虑了流体力、TPCL运动等因素，具有更高的精度。(C)2019爱思唯尔有限公司版权所有。
Particle impacting on a liquid surface is frequently observed in natural and industrial processes. This study numerically investigates the critical sinking behaviour after the impact of hydrophobic micron particles on liquid surfaces. The effects of contact angle theta, density ratio D, and the Reynolds number Re on the motions of the particle and TPCL are analyzed. The dimensionless penetration depth of the particle increases with increasing theta and D, whereas the effect of Re is negligible. The relationship between the TPCL position on the particles and the normalised particle displacement is only determined by theta and almost unaffected by Re and D. For the critical sinking of hydrophobic micron particles, both fluid force and surface tension play important roles in the conversion of particle kinetic energy. A dimensionless energy conservation equation is constructed, based on which a simple criterion of critical sinking is proposed. The expression of this criterion is obtained based on the semi-empirical expressions describing the relationships of each dimensionless accumulated work with Re, theta, and D obtained from simulation results. Compared with existing criteria, the proposed criterion is more accurate because it considers the fluid force, TPCL movement, and other factors reasonably. (C) 2019 Elsevier Ltd. All rights reserved.