The motion of a neutrally buoyant particle of an elliptic shape in two dimensional shear flow: A numerical study
The motion of a neutrally buoyant particle of an elliptic shape in two dimensional shear flow: A numerical study
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DOI：
10.1063/1.4928917
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发表时间：
2014-05
影响因子：
4.6
通讯作者：
Shih-Lin Huang;Shih-Di Chen;T. Pan;Chien-Cheng Chang;C. Chu
中科院分区：
文献类型：
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作者：
Shih-Lin Huang;Shih-Di Chen;T. Pan;Chien-Cheng Chang;C. Chu
本文采用直接数值模拟的方法，研究了自由运动的椭圆中性浮力粒子在二维剪切流中的运动。剪切流动中的椭圆型粒子，最初被放置在两壁中间时，根据粒子雷诺数Re=Grra2/ν保持旋转或有一个固定的倾角，其中Gr为剪切速率，ra为椭圆粒子的半长轴，ν为流体的运动粘度。由旋转运动向静止方向转变的临界粒子雷诺数Recr取决于长径比AR = rb/ra和约束比K = 2ra/H，其中rb为椭圆粒子的半短轴，H为两壁之间的距离。尽管这两个参数的增加都会导致Recr的增加，但其动力机制是明显的。AR的变化引起几何形状的变化；然而，K的变化影响壁效应。stati……
In this article, we investigate the motion of a neutrally buoyant particle of an elliptic shape freely moving in two dimensional shear flow by direct numerical simulation. An elliptic shape particle in shear flow, when initially being placed at the middle between two walls, either keeps rotating or has a stationary inclination angle depending on the particle Reynolds number Re=Grra2/ν, where Gr is the shear rate, ra is the semi-long axis of the elliptic particle, and ν is the kinetic viscosity of the fluid. The critical particle Reynolds number Recr for the transition from a rotating motion to a stationary orientation depends on the aspect ratio AR = rb/ra and the confined ratio K = 2ra/H, where rb is the semi-short axis of the elliptic particle and H is the distance between two walls. Although the increasing of either parameters makes an increase in Recr, the dynamic mechanism is distinct. The AR variation causes the change of geometry shape; however, the K variation influences the wall effect. The stati...