气固稀相流中颗粒沉积和聚集的分子动力学模拟  

MOLECULAR DYNAMICS SIMULATION OF PARTICLE DEPOSITION AND AGGLOMERATION IN TWO-PHASE DILUTE FLOW

作　　者：李水清[1] J.S.Marshall A.Ratner 姚强[1] 

机构地区：[1]清华大学热能工程系 热科学与动力工程教育部重点实验室,北京100084 [2]爱荷华大学机械与工业工程系 水利科学与工程所,爱荷华城ia52246

出　　处：《工程热物理学报》2007年第6期1035-1038,共4页Journal of Engineering Thermophysics

基　　金：国家自然科学基金项目资助(No.50306012);国家重点基础研究发展规划项目资助(2002CB211600)

摘　　要：本文在分子动力学模拟基础上采用了考虑黏附作用的JKR理论取代传统Hertz理论作为颗粒间作用力,并吸取了DEM中滑动摩擦、滚动摩擦和扭动摩擦的思想建立一种细颗粒碰撞和团聚过程的多时间尺度粒子动力学模拟方法.成功地实现了颗粒在纤维上沉积过程的模拟,结果表明微米颗粒的Van der Waals力量纲约是曳力2～10倍,中心流线附近颗粒更易于在纤维上沉积,初始沉积的颗粒则会在纤维上形成"遮挡"效应。The multi-time step computational approach, developed for efficient molecular/granular dynamics simulation of disperse flow with adhesive fine particulates, are firstly applied to simulate particle deposition on a fiber under periodic conditions. The JKR theory accounting for adhesion forces, instead of Hertz contact theory, of two spheres is considered, and then sliding, rolling and twisting friction are modified in current work. The results indicate that the magnitude of Van der Waals force of 1 μm particles is about 2-10 times of those of drag force. The particle locating at the vicinity of mid-line of fiber has overwhelming possibility to deposit and then grows to a dendrite. The dendrite formation by the initial deposition will bring shadow effects to the incoming particles at the upstream side of fiber.

关 键 词：分子动力学模拟 离散元模拟 颗粒聚集 

分 类 号：TK16[动力工程及工程热物理—热能工程] O357[理学—流体力学]