Li Yingxiang, Xing Baohua, Ding Mingming, Shi Tongfei, Sun Zhaoyan
State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, P. R. China.
School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei 230026, P. R. China.
Soft Matter. 2021 Oct 20;17(40):9154-9161. doi: 10.1039/d1sm01271a.
By incorporating a distance function into the finite element simulation, we investigate the flow-driven competition between two soft capsules passing through a narrow pore, employing the arbitrary Lagrangian-Eulerian formulation to satisfy the boundary conditions for fluid flow and capsule deformation. In our simulations, the motion and deformation of the capsules can be described in an intuitive manner, and the order in which capsules of different sizes pass through a pore can be clearly determined. Meanwhile, when the capsules are near the narrow pore, the change of the flow field is also very interesting and can be expressed intuitively. It is shown that, driven by the Poiseuille flow, the larger capsule has a stronger tendency to pass through the pore than the small one, which can be attributed to the greater resistance and the volume advantage of the larger capsule. In addition, we demonstrate that this tendency can be reversed by changing the inlet velocity and setting the initial position of the smaller capsule closer to the axis of the pore. And as long as the large one passes through first, the small one will offset the axis to the same orientation as the initial, while the large one always moves along the axis.
通过将距离函数纳入有限元模拟，我们研究了两个软胶囊通过狭窄孔隙时的流动驱动竞争，采用任意拉格朗日 - 欧拉公式来满足流体流动和胶囊变形的边界条件。在我们的模拟中，胶囊的运动和变形可以以直观的方式描述，并且不同尺寸的胶囊通过孔隙的顺序可以清楚地确定。同时，当胶囊靠近狭窄孔隙时，流场的变化也非常有趣并且可以直观地表达出来。结果表明，在泊肃叶流的驱动下，较大的胶囊比较小的胶囊有更强的通过孔隙的倾向，这可归因于较大胶囊更大的阻力和体积优势。此外，我们证明通过改变入口速度并将较小胶囊的初始位置设置得更靠近孔隙轴线，可以逆转这种倾向。并且只要较大的胶囊先通过，较小的胶囊就会向与初始相同的方向偏移轴线，而较大的胶囊总是沿着轴线移动。
