瓶颈中颗粒流动的堵塞行为  

Jamming behavior of granular flow in a bottleneck

作　　者：欧阳鸿武[1] 程亮[1] 黄立华[1] 黄誓成[1] 王琼[1] 刘卓民[1] 

机构地区：[1]中南大学粉末冶金国家重点实验室,长沙410083

出　　处：《粉末冶金材料科学与工程》2013年第1期13-19,共7页Materials Science and Engineering of Powder Metallurgy

基　　金：国家自然科学基金创新团队(51021063);国家自然科学基金资助项目(50574103,10476034)

摘　　要：颗粒物质流经瓶颈时难以预知的堵塞现象是1个古老且令人困惑的难题。本文选取3种球形颗粒,统计分析颗粒流出小于临界开口尺寸锥形瓶颈的颗粒数,探讨堵塞转变的概率分布特征和物理机制。结果显示:(1)堵塞前流出瓶颈的颗粒数概率分布存在1个峰值,峰值前概率呈幂函数增长,峰值后概率为指数衰减;(2)颗粒的密度、弹性系数及表面摩擦等因素影响颗粒间的接触时间、堵塞结构稳定性和堵塞概率分布。当瓶颈开口尺寸低于临界尺寸,且颗粒流态由稀疏流转变为密集流后,堵塞转变必将发生。Jamming of granular matter in a bottleneck flow occurs widespread without predicting, which is an ancient and confusing question. In the present work, the number of the grains discharged from the cone-shaped bottleneck below critical size before jamming was measured statistically; the characteristics of probability distribution and the physical mechanism of jamming with three kinds of spherical grains were explored. The results show： （1） The probability distribution of the number of discharging grains before jamming shows a peak; a power law growth to the left, and an exponential tail to the right; （2） The density, coefficient of elasticity and the surface friction of the spherical grains have effects on the contact time between grains, the stability of jamming configuration and probability distribution of jamming size. If the bottleneck size is below critical size and the dilute flow shift into dense flow, jamming will inevitably occur.

关 键 词：颗粒流动 堵塞 瓶颈 

分 类 号：TQ019[化学工程]