Institute for Mechanical Systems, Department of Mechanical and Process Engineering, ETH Zürich, Leonhardstrasse 21, 8092 Zürich, Switzerland.
Computational Sciences and Engineering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
Phys Rev Lett. 2018 Aug 3;121(5):054502. doi: 10.1103/PhysRevLett.121.054502.
We combine numerical simulations and an analytic approach to show that the capture of finite, inertial particles during flow in branching junctions is due to invisible, anchor-shaped three-dimensional flow structures. These Reynolds-number-dependent anchors define trapping regions that confine particles to the junction. For a wide range of Stokes numbers, these structures occupy a large part of the flow domain. For flow in a V-shaped junction, at a critical Stokes number, we observe a topological transition due to the merger of two anchors into one. From a stability analysis, we identify the parameter region of particle sizes and densities where capture due to anchors occurs.
我们结合数值模拟和解析方法表明，在分叉处流动中捕获有限的惯性颗粒是由于不可见的、锚状的三维流动结构所致。这些依赖于雷诺数的锚点定义了捕获区域，将颗粒限制在连接点处。对于广泛的斯托克斯数范围，这些结构占据了流动区域的很大一部分。对于 V 形连接点中的流动，在一个临界斯托克斯数下，我们观察到由于两个锚点合并成一个而导致的拓扑转变。通过稳定性分析，我们确定了由于锚点而发生捕获的颗粒尺寸和密度的参数区域。
