Department of Mathematics, University of Houston, Houston, Texas 77204, USA.
Department of Mathematics, University of Houston, Houston, Texas 77204, USA and Department of Mathematics, Hong Kong Baptist University, Hong Kong.
Phys Rev E. 2017 Dec;96(6-1):063103. doi: 10.1103/PhysRevE.96.063103. Epub 2017 Dec 4.
In this article, we present a numerical study of the dynamics of two disks sedimenting in a narrow vertical channel filled with an Oldroyd-B fluid. Two kinds of particle dynamics are observed: (i) a periodic interaction between the two disks, and (ii) the formation of a two-disk chain. For the periodic interaction of the two disks, two different motions are observed: (a) the two disks stay far apart and interact periodically, and (b) the two disks interact closely and then far apart in a periodic way, like the drafting, kissing, and tumbling of two disks sedimenting in a Newtonian fluid, due to a weak elastic force. Concerning the formation of a two-disk chain occurring at higher values of the elasticity number, either a tilted chain or a vertical chain is observed. Our simulations show that, as expected, the values of the elasticity and Mach numbers are the determining factors concerning the particle chain formation and its orientation.
本文研究了在充满 Oldroyd-B 流体的狭窄垂直通道中沉降的两个圆盘的动力学。观察到两种颗粒动力学：（i）两个圆盘之间的周期性相互作用，和（ii）双盘链的形成。对于两个圆盘的周期性相互作用，观察到两种不同的运动：（a）两个圆盘保持很远的距离并周期性地相互作用，和（b）两个圆盘以类似于牛顿流体中沉降的两个圆盘的牵伸、亲吻和翻滚的方式紧密相互作用，然后以周期性的方式远离，这是由于弱弹性力。关于在更高的弹性数下发生的双盘链的形成，观察到倾斜链或垂直链。我们的模拟表明，正如预期的那样，弹性和马赫数的值是关于颗粒链形成及其方向的决定因素。
