颗粒的有限尺寸对颗粒在均匀各向同性湍流中扩散的影响  

The Size Effect on the Dispersion of a Particle in a Homogeneous Isotropic Turbulence

作　　者：谢定国[1] 

机构地区：[1]浙江大学力学系

出　　处：《应用数学和力学》1990年第6期547-554,共8页Applied Mathematics and Mechanics

摘　　要：本文指出固体颗粒对流体湍流运动的响应有不同的机理,颗粒受大涡的粘性拖动,但受小涡的随机碰撞.基于这种原理,本文计算了有限尺寸的固体颗粒在均匀各向同性湍流中的扩散.结果显示存在着二种相互抵消的效应:颗粒的惯性使颗粒长期扩散系数上升,而颗粒尺寸使颗粒的长期扩散系数下降.The mechanism of the response motion of a suspended particle to turbulent motion of its surrounding fluid is different according to size of turbulent eddies. The particle is dragged by the viscous force of large eddies, and meanwhile driven randomly by small eddies. Based on this understanding, the dispersion of a particle with finite size in a homogeneous isotropic turbulence is calculated in this study. Results show that there are two competing effects: when enhanced by the inertia of a particle, the long-term particle diffusivity is reduced by the finite size of the particle.

关 键 词：多相流 湍流 固体颗粒 尺寸 扩散 

分 类 号：O359[理学—流体力学]