Expanding holes driven by convectionlike flow in vibrated dense suspensions.
Expanding holes driven by convectionlike flow in vibrated dense suspensions.
复制标题
由振动致密悬浮液中的类对流流动驱动的膨胀孔。
DOI：
10.1103/physreve.79.066308
复制
发表时间：
2009
期刊：
影响因子：
--
通讯作者：
M. Sano
中科院分区：
文献类型：
--
作者：
H. Ebata;S. Tatsumi;M. Sano
在准二维 (2D) 和准一维 (1D) 系统中研究了分散在硅油中的各种粉末的垂直振动悬浮液的表面不稳定性。当振动加速度超过临界值时，平坦表面在有限振幅扰动下变得不稳定。我们在准二维系统中发现了不断扩大的孔或粘性指状图案，并且在准一维系统中发现了干燥区域和潮湿区域之间的分离。我们表明，这些不稳定性伴随着其边缘的类对流流动，并且在准一维系统中，类对流流动的高度可以通过加速度、振动频率、分散粉末的直径、悬浮液的平均密度和硅油的粘度来缩放。我们提出了一个简单的模型来解释类对流流的缩放和同心运动。
Surface instabilities in vertically vibrated suspensions of various powders dispersed in silicone oil are investigated in quasi-two-dimensional (2D) and quasi-one-dimensional (1D) systems. As vibration acceleration exceeded a critical value, the flat surface became unstable against a finite-amplitude perturbation. We found an expanding hole or viscous fingerlike pattern in the quasi-2D system and segregation between dried and wet areas in the quasi-1D system. We show that these instabilities are accompanied by convectionlike flow at their rim and in the quasi-1D system, the height of the convectionlike flow can be scaled by acceleration, vibration frequency, diameter of the dispersed powder, mean density of the suspension, and viscosity of silicone oil. We propose a simple model that accounts for the scaling and concentric motion of the convectionlike flow.