The translational and rotational motions of a cylindrical particle in a granular shear flow inside a split bottom Couette cell
The translational and rotational motions of a cylindrical particle in a granular shear flow inside a split bottom Couette cell
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DOI：
10.1063/5.0015175
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发表时间：
2020-07-01
影响因子：
4.6
通讯作者：
Wu, Huixuan
中科院分区：
文献类型：
--
作者：
Tao, Xingtian;Wu, Huixuan
采用磁颗粒跟踪技术测量了样品颗粒在库埃特细胞颗粒流中的运动。这项技术允许在不透明的环境中同时测量单个颗粒的平移和旋转。各向异性试样颗粒为长径比为1的圆柱体，流中的其他颗粒为球状颗粒。运动轨迹表明，所研究的具有分裂底部的Couette细胞中的粒子以层状结构运动。取向分布表明，即使长径比较低且剪切运动不应引起强烈的排列，柱状颗粒也倾向于向特定方向排列。采用基于符号的方法来研究空间层间的跳跃和偏好方向之间的翻转。结果表明，粒子停留在首选态的时间比跃迁的时间长得多。此外，一个跳跃的粒子有更高的机会翻转。在体流中，平动能沿径向变化较大。平动动能的大小通常比旋转动能大得多。
The motion of a sample particle in a Couette-cell granular flow is measured using the magnetic particle tracking technology. This technology allows simultaneous measurements of translation and rotation of an individual grain in an opaque environment. The anisotropic sample particle is a cylinder with an aspect ratio 1, and the other grains in the flow are spherical balls. The trajectory shows that the particle in the studied Couette cell with a split bottom moves in a layered structure. The orientation distribution shows that the cylindrical particle prefers to align in specific directions, even though the aspect ratio is low and the shear motion should not cause strong alignment. A symbolic-based method is used to examine the jumping between spatial layers and the flipping among preferred directions. The result shows that the duration of particle staying in a preferred state is much longer than the duration of transition. In addition, a jumping particle has a higher chance to flip. In the bulk flow, the translational energy varies significantly along the radial direction. The magnitude of translational kinetic energy is generally much larger than the rotational motion.