Motion and equilibrium position of elliptical and rectangular particles in a channel flow of a power-law fluid
Motion and equilibrium position of elliptical and rectangular particles in a channel flow of a power-law fluid
复制标题
幂律流体通道流中椭圆形和矩形粒子的运动和平衡位置
DOI：
10.1016/j.powtec.2020.09.028
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发表时间：
2021-01-02
影响因子：
5.2
通讯作者：
Ku, Xiaoke
中科院分区：
文献类型：
--
作者：
Hu, Xiao;Lin, Jianzhong;Ku, Xiaoke
用格子Boltzmann方法研究了幂律流体槽道流中椭圆和矩形颗粒的惯性迁移。通过与前人计算结果的比较，验证了数值方法和程序的正确性.讨论了流体的幂律指数n、颗粒形状、颗粒长径比a、堵塞比k和雷诺数Re对颗粒运动轨迹和平衡位置的影响。结果表明，椭圆形和矩形颗粒最终将在一个横向平衡位置振荡。颗粒从初始位置到稳定平衡位置的距离，矩形颗粒最短，椭圆颗粒次之，圆形颗粒和方形颗粒最短;剪切稀化流体最短，牛顿流体次之，剪切增稠流体最短。对于矩形颗粒，该距离随着Re的增加而减小，但对于椭圆形颗粒，该距离对Re的依赖性不如矩形颗粒明显。长径比和堵塞比越大的颗粒到达平衡位置的速度越快。从平衡位置到通道中心线的横向距离随着k的增加而减小，并且对于椭圆形和矩形颗粒都随着a的减小而减小。对于α较大的颗粒，横向距离随Re的增大而减小，而对于α较小的颗粒，横向距离与Re的关系依赖于n。(C)2020爱思唯尔B. V.保留所有权利。
The inertial migration of the elliptical and rectangular particles in a channel flow of a power-law fluid is studied using the lattice Boltzmann method. The numerical method and code are validated by comparing the present results with the previous ones. Effects of power-law index (n) of the fluid, particle shape, particle aspect ratio (a), blockage ratio (k) and Reynolds number (Re) on the particle trajectory and equilibrium position are discussed. The results show that the elliptical and rectangular particles will finally oscillate in a lateral equilibrium position. The distance for the particle from its initial position to the stable equilibrium position is the shortest for the rectangular particle, then followed for the elliptical particle and finally for the circular particle and square particle, the distance is the shortest for the shear-thinning fluid, then followed for the Newtonian fluid and finally for the shear-thickening fluid. This distance for the rectangular particle decreases with increasing Re, but the dependence of the distance on Re for the elliptical particle is not as obvious as that for the rectangular particle. The particle with larger aspect ratio and blockage ratio gets to the equilibrium position faster. The lateral distance from the equilibrium position to the channel centerline is reduced with increasing k, and with decreasing a for both elliptical and rectangular particles. For the particles with larger a, the lateral distance is reduced with the increase of Re, but the relationship between the lateral distance and Re for the particles with smaller a is dependent on n. (C) 2020 Elsevier B.V. All rights reserved.