基于CFD-DEM对激光熔覆载气输送喘粉问题的数值模拟研究  

Numerical Simulation Study on the Problem of Powder Panting in Carrier Gas Transportation by Laser Cladding Based on CFD-DEM

作　　者：张钰铎 邢飞 刘伟军[1] 卞宏友[1] 锁红波 Zhang Yuduo;Xing Fei;Liu Weijun;Bian Hongyou;Suo Hongbo(Shenyang University of Technology,Shenyang110870,Liaoning,China;Nanjing Zhongke Raycham Laster Technology Company,Nanjing210038,Jiangsu,China)

机构地区：[1]沈阳工业大学,辽宁沈阳110870 [2]南京中科煜宸激光技术有限公司,江苏南京210038

出　　处：《应用激光》2024年第4期49-58,共10页Applied Laser

基　　金：辽宁省高校创新团队(202114026);辽宁省“兴辽英才计划”项目(XLYC19022022)。

摘　　要：针对激光熔覆载气输送过程中经常出现的喘粉问题,从输送管道的提升角度、折弯半径、提升高度以及气流量4个方面进行模拟分析,研究出现喘粉现象的原因。数值模拟通过离散单元法(DEM)求解离散颗粒运动和受力,通过计算流体力学(CFD)求解连续相流场,两者相互耦合组成离散元-计算流体力学(DEM-CFD)模型。仿真结果表明,造成喘粉现象的起因为颗粒在流经弯管的位置分布不同,处于弯管外侧的颗粒会维持该状态直至竖直管段扩散,处于弯管内侧和中间的颗粒会不断地与壁面发生碰撞,这种差异导致颗粒在弯管段的运动时间不同,从而出现某段时间粉量剧增的情况。对喘粉现象的影响程度从大到小为气流量、提升高度、折弯半径、提升角度。为保证输送过程连续稳定,气流量应大于6 L/min,在满足输送条件的情况下以45°提升角度输送,减小折弯半径并且提升高度不高于2.5 m。To address the issue of powder surge in laser cladding carrier gas transportation,a comprehensive simulation analysis was conducted focusing on four key parameters:lifting angle,bending radius,lifting height,and gas flow rate.The study aimed to elucidate the underlying causes of powder surge.The discrete element method(DEM)is used to solve the motion and force of discrete particles,and the computational fluid dynamics(CFD)is used to solve the continuous phase flow field,which is coupled with each other to form a discrete element-computational fluid dynamics(DEM-CFD)model.The simulation results show that the phenomenon of wheezing powder is caused by the position distribution of particles flowing through the elbow.The particles outside the elbow maintain this state until they diffuse in the vertical pipe section,and the particles inside and in the middle of the elbow constantly collide with the wall surface,which leads to different movement time of particles in the elbow section,resulting in a sharp increase in powder amount in a certain period of time.The influencing factors of powder surge are gas flow rate,lifting height,bending radius and lifting angle from large to small.In order to ensure the continuous and stable transportation process,the air flow rate should be greater than 6L/min,and the transportation should be carried at 45°lifting angle under the condition of meeting the transportation conditions,and the bending radius should be reduced and the lifting height should not be higher than 2.5m.

关 键 词：气力输送 喘粉问题 管路结构 数值模拟 质量流量 

分 类 号：TH138[机械工程—机械制造及自动化]