料斗结拱及改流体的数值仿真研究  

Numerical Simulation Study on Arch in Hopper and Cone-in-cone Insert

作　　者：谢宇[1] 韩保红[1] 程兆刚[1] 段云龙 

机构地区：[1]军械工程学院,河北石家庄050003 [2]燕山机械厂,河北张家口075041

出　　处：《计算机仿真》2013年第8期221-224,共4页Computer Simulation

摘　　要：关于料斗出口优化设计问题,为了研究料斗出料口尺寸与颗粒直径比率较小时,物料发生结拱的原因以及改流体对流动性能的影响,并解决实验中颗粒间接触力测量困难的问题,采用离散单元法(DEM)对料斗结拱模型和改流体模型进行了数值仿真。用三维离散元软件PFC3D建立颗粒在料斗中结拱模型,通过能量累积函数观察结拱时间,并在模型中显示结拱后颗粒间接触力,分析接触力特点;然后在前面模型中增加改流体,并仿真颗粒的流动,与结拱模型对比,并分析了影响颗粒流动的原因。结果表明,颗粒直径与出料口直径比率较大时,孔隙率减小导致颗粒间接触力增大,容易发生结拱;增加改流体可承担出料口处颗粒间压力,增大了孔隙率,破坏了结拱形成条件,改善了颗粒的流动性能。To study the reason of arch forming and the influence of the cone-in-cone insert when the ratio of the outlet size of the hopper to the diameter of the particle was little,and to solve the problem of contact force measuring hardly in the experiment,the discrete element method （DEM） was used to simulate the arch forming model and the cone-in-cone insert model.A three-dimensional DEM software PFC3D was used to build a model of an arch in the hopper.It can be observed from the accumulate energy function when the arch was formed.The contact force can be shown in the model to analysis its characteristic.A cone-in-cone insert then was added in the foregoing model to simulate the flow of the particles.A comparison was drawn between the two models to analysis the cause of arch forming.The results show that the decrease porosity leads to the increase contact force which causes arch forming easily,when the ratio of the diameter of the particle to the outlet size of the hopper is large.Besides,the cone-in-cone insert can undertake the pressure between the particles around the outlet of the hopper.It increases the porosity,breaks the condition of the arch forming,and improves the flow ability of the particles.

关 键 词：离散单元法 料拱 仿真 改流体 

分 类 号：TH128[机械工程—机械设计及理论]