【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。更多还原

【Abstract】 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.更多还原