Liao C C, Hsiau S S, To Kiwing
Department of Mechanical Engineering, National Central University, Jhongli, Taiwan 32001, Republic of China.
Phys Rev E Stat Nonlin Soft Matter Phys. 2010 Jul;82(1 Pt 1):010302. doi: 10.1103/PhysRevE.82.010302. Epub 2010 Jul 30.
We study the effects of interstitial fluid viscosity on the rates of dynamical processes in a thin rotating drum half-filled with monodisperse glass beads. The rotating speed is fixed at the rolling regime such that a continuously flowing layer of beads persists at the free surface. While the characteristic speed of a bead in the flowing layer decreases with the fluid viscosity μ, the mixing rate of the beads is found to increase with μ. These findings are consistent to a simple model related to the thickness of the flowing layer. In addition, our results indicate a possible transition from the inertial limit regime to the viscous limit regime (reported previously by S. Courrech du Pont [Phys. Rev. Lett. 90, 044301 (2003)]) when the Stokes number is reduced.
我们研究了间隙流体粘度对一个半满单分散玻璃珠的薄旋转鼓中动力学过程速率的影响。旋转速度固定在滚动状态，使得在自由表面存在一层持续流动的珠子。虽然流动层中珠子的特征速度随流体粘度μ降低，但发现珠子的混合速率随μ增加。这些发现与一个与流动层厚度相关的简单模型一致。此外，我们的结果表明，当斯托克斯数降低时，可能会从惯性极限状态转变为粘性极限状态（先前由S. Courrech du Pont报道[《物理评论快报》90, 044301 (2003)]）。
