颗粒移动床内不稳定运动的计算颗粒动力学模拟  

Computational granular dynamics simulation of unsteady movement in particle moving bed

作　　者：赵永志[1] 程易[1] 金涌[1] 

机构地区：[1]清华大学化学工程系绿色反应工程与工艺北京市重点实验室,北京100084

出　　处：《化工学报》2007年第9期2216-2224,共9页CIESC Journal

基　　金：国家自然科学基金项目(20306012);全国博士学位论文作者专项资金项目(200245);中国博士后基金项目(2005038061)~~

摘　　要：采用考虑滚动摩擦的三方程离散单元法(DEM)模型对侧开孔的移动床中的颗粒流动进行了数值研究。结果表明,计算颗粒动力学(CGD)方法可对复杂颗粒系统内颗粒的运动行为进行准确的预测,包括时均速度场和脉动速度场。讨论了模型中颗粒摩擦参数的重要影响,并对颗粒流动表现出的间歇现象进行了分析。颗粒流动与流体流动有相似之处,都存在随机的脉动,但颗粒流的随机脉动机理与流体中的湍流机理有很大不同,颗粒流动会表现出很强的不连续性。The granular flow in a particle moving bed with a side exit at the bottom was simulated by using a three-equation discrete element method （DEM） model that considers rolling friction. It was demonstrated that the computational granular dynamics （CGD） method can accurately predict the flow behavior of the particles in the complex granular systems, including the time averaged velocity field and the velocity fluctuations. The granular flow had certain similarities to fluid flow, such as the random fluctuation of velocities. However, the physical mechanism for the intermittent behavior in the granular flow was different from fluid flow. The granular flow showed great discontinuity. The friction coefficients of particles, which greatly affected the dynamics in the granular flow were discussed in the numerical simulations.

关 键 词：离散单元法 计算颗粒动力学 移动床 数值模拟 

分 类 号：TQ018[化学工程]