Vesicle migration and spatial organization driven by flow line curvature.
Vesicle migration and spatial organization driven by flow line curvature.
复制标题
流线曲率驱动的囊泡迁移和空间组织。
DOI：
10.1103/physrevlett.106.028101
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发表时间：
2011
影响因子：
8.6
通讯作者：
C. Misbah
中科院分区：
文献类型：
--
作者：
G. Ghigliotti;Abtin Rahimian;G. Biros;C. Misbah
可变形实体的跨流线迁移在许多问题中是必不可少的，例如工业颗粒流、DNA分选和血液流变学。使用二维数值实验，我们已经发现，囊泡悬浮在流与弯曲的流线迁移到高流线曲率，这是高剪切速率的区域的区域。研究发现，气泡的迁移速度是法向应力差和流动曲率的普适函数。这一发现定量地证明了微观量（迁移）和宏观量（法向应力差）之间的直接耦合。此外，模拟与多个囊泡揭示了自组织，这对应于隔离，在一个边缘更接近内筒，导致囊泡之间的微妙的相互作用。这种分离效应可能对囊泡流的流变学产生显著影响。
Cross-streamline migration of deformable entities is essential in many problems such as industrial particulate flows, DNA sorting, and blood rheology. Using two-dimensional numerical experiments, we have discovered that vesicles suspended in a flow with curved flow lines migrate towards regions of high flowline curvature, which are regions of high shear rates. The migration velocity of a vesicle is found to be a universal function of the normal stress difference and the flow curvature. This finding quantitatively demonstrates a direct coupling between a microscopic quantity (migration) and a macroscopic one (normal stress difference). Furthermore, simulations with multiple vesicles revealed a self-organization, which corresponds to segregation, in a rim closer to the inner cylinder, resulting from a subtle interaction among vesicles. Such segregation effects could have a significant impact on the rheology of vesicle flows.