Spheres in the vicinity of a bifurcation: elucidating the Zweifach-Fung effect
Spheres in the vicinity of a bifurcation: elucidating the Zweifach-Fung effect
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DOI：
10.1017/s0022112010006567
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发表时间：
2011-05-01
影响因子：
3.7
通讯作者：
Coupier, G.
中科院分区：
文献类型：
--
作者：
Doyeux, V.;Podgorski, T.;Coupier, G.
解决了悬浮液在分成两个不等流速分支的分叉通道中分裂的问题。正如长期以来所观察到的，特别是在血流研究中，颗粒的体积分数通常在高流速分支中增加，而在低流速分支中减少。在文献中，这种现象有时被解释为颗粒对这种高流速分支的某种吸引力的结果。在本文中，我们通过微流体实验和二维模拟重点关注这种吸引力的存在，并清楚地表明这种吸引力不会发生，而是相反，指向低流速分支。给出了这种吸引力的论据，并对文献中有时存在误导性的论点进行了讨论。最后，高流速支管中颗粒的富集主要是入口支管中初始分布的结果，这表明壁附近必然存在一些损耗。
The problem of the splitting of a suspension in bifurcating channels divided into two branches of non-equal flow rates is addressed. As has long been observed, in particular in blood flow studies, the volume fraction of particles generally increases in the high-flow-rate branch and decreases in the low-flow-rate branch. In the literature, this phenomenon is sometimes interpreted as the result of some attraction of the particles towards this high-flow-rate branch. In this paper, we focus on the existence of such an attraction through microfluidic experiments and two-dimensional simulations and show clearly that such an attraction does not occur but is, on the contrary, directed towards the low-flow-rate branch. Arguments for this attraction are given and a discussion on the sometimes misleading arguments found in the literature is given. Finally, the enrichment of particles in the high-flow-rate branch is shown to be mainly a consequence of the initial distribution in the inlet branch, which shows necessarily some depletion near the walls.