绕流中颗粒与柱体碰撞和磨损的直接数值模拟  

Direct numerical simulation of collisions and erosions between particles and cylinder in circular cylinder wake

作　　者：闫洁[1] 李文春[1] 樊建人[1] 岑可法[1] 

机构地区：[1]浙江大学热能工程研究所能源洁净利用国家重点实验室,浙江杭州310027

出　　处：《浙江大学学报（工学版）》2007年第4期589-593,共5页Journal of Zhejiang University：Engineering Science

基　　金：国家自然科学基金重点资助项目(50236030)

摘　　要：为了研究圆柱近壁区颗粒与柱体的碰撞和磨损问题,采用高精度有限差分的方法对圆柱绕流进行了直接数值模拟.在获得高精度计算流场信息的基础上,采用Lagrangian方法追踪了颗粒在圆柱近壁区的运动.利用非弹性碰撞模型的壁面磨损量经验公式,进行了壁面磨损量的计算,详尽考察了不同粒径的颗粒与壁面的碰撞磨损情况.研究发现,随着颗粒粒径的增大,颗粒与壁面的碰撞频率变高;局部碰撞频率的曲线较为特殊,粒径较大颗粒的碰撞多发生在与来流方向平行的中心轴线处,而小粒径颗粒的碰撞则要外移一定的位置.还发现颗粒对壁面的磨损率也是随粒径的增大而增大.颗粒的冲击角对壁面的磨损同样起着至关重要的影响,对于塑性材料,冲击角为20°-30°时,壁面的磨损率最大.To investigate collisions and erosions of particles and cylinder in the near field of circular cylinder wake, direct numerical simulation of a circular cylinder wake flow was proposed by using high-order finite difference method. Based on accurate gas-field simulation, Lagrangian method was employed to trace the particles. With the empirical formula of calculating erosion in the inelastic collision model, the associated collision pattern of particles with different Stokes numbers was examined in detail. Simulation results indicated that the increase of particles＇ diameters leads to increasing the collision frequency, and that the collision of the bigger particles and the cylinder occurs in the center axis that parallels inflow direction, while the collision positions of the smaller particles move backward. Erosion ratio also increases with increasing diameters of particles. Effect of the impact angles is also significant. For plastic material, the erosion ratio is highest at 20°～430°.

关 键 词：直接数值模拟 圆柱绕流 碰撞 磨损 

分 类 号：O357[理学—流体力学]