Numerical study on dynamic sorting of a compliant capsule with a thin shell
Numerical study on dynamic sorting of a compliant capsule with a thin shell
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薄壳柔顺胶囊动态分选的数值研究
DOI：
10.1016/j.compfluid.2015.02.021
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发表时间：
2015-07
期刊：
影响因子：
--
通讯作者：
XY Lu
中科院分区：
文献类型：
--
作者：
HL Ye;黄海波;XY Lu
对顺应性胶囊进行分类是一个有趣的研究课题。本文采用简单的分叉微通道对不同刚度的颗粒进行分选。数值研究了通道内柔顺粒子的行为。采用格子Boltzmann方法（LBM）和格子弹簧模型（LSM）分别求解流体流动和颗粒变形。流体和固体求解器通过插值反弹格式耦合。两个基准问题被用来验证我们的方法。一个是柔顺胶囊在通道中的运动，另一个是胶囊在简单剪切流中的变形。计算结果与文献值在定量上一致。利用胶囊在剪切流中的旋转特性，提出了一种简单易行的分叉微通道，可对不同刚度的胶囊进行分选。在该微通道中，初始偏移和剪切应力引起胶囊的旋转和侧向迁移，并且流量比由出口压力决定。初始偏移效应和通量比效应之间的竞争是导致分选机制的主要原因。与其他几何模型相比，本模型更方便、更有效地筛选出所需的微胶囊。
Sorting compliant capsules is an interesting research topic. In this paper, a simple bifurcated micro-channel is used to sort the particles with different rigidities. The behavior of a compliant particle inside the channel is investigated numerically. The fluid flow and the particle’s deformation are solved by Lattice Boltzmann Method (LBM) and Lattice Spring Model (LSM), respectively. The fluid and solid solvers are coupled through interpolated bounce-back scheme. Two benchmark problems are used to validate our method. One is the motion of a compliant capsule in a channel and the other is the deformation of a capsule inside a simple shear flow. The results are quantitatively consistent with those in literature. By taking advantage of the rotating of capsules in shear flow, a simple distinguished bifurcated micro-channel is proposed to sort capsules with different rigidities. In this micro-channel, the initial offset and shear stress induce the rotating and lateral migration of the capsule and flux ratio is determined by the outlet pressures. The competition between the effect of initial offset and flux ratio contributes to the sorting mechanism. Compared to other micro-channels with different geometrical models, present one is more convenient and may be more efficient to screen the microcapsule we want.