基于CFD-DEM耦合的磨粒流微小孔加工数值分析与试验  

Numerical analysis and experiment of abrasive flow machining microhole structure based on CFD-DEM coupling

作　　者：李俊烨[1,2] 苏宁宁 胡敬磊 杨兆军[2] 盛亮 张心明[1] Li Junye;Su Ningning;Hu Jinglei;Yang Zhaojun;Sheng Liang;Zhang Xinming(College of Mechanical and Electric Engineering,Changchun University of Science and Technology,Changchun 130022,China;College of Mechanical and Electric Engineering,Jilin University,Changchun 130012,China)

机构地区：[1]长春理工大学机电工程学院,长春130022 [2]吉林大学机械科学与工程学院,长春130012

出　　处：《农业工程学报》2018年第16期80-88,共9页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家自然科学基金项目(51206011);吉林省科技发展计划项目(20160101270JC;20170204064GX)

摘　　要：由于当前具有微小孔的结构等零部件加工难度大,精度要求高,传统加工方法无法满足现有的加工精度要求,该文采用一种软性加工方法—磨粒流加工技术,实现微小孔结构精密加工。采用CFD(computational fluid dynamics)和DEM(discrete element method)相结合的方法对磨粒流加工过程进行数值分析。在数值分析过程中,考虑颗粒对壁面的碰撞作用,对不同入口速度条件下的流体和颗粒的分布状态进行对比分析,揭示磨粒流微切削作用行为,通过对材料去除机理的分析揭示颗粒对壁面的作用规律。数值模拟结果表明:随着入口速度的增大,颗粒与零件表面的摩擦与碰撞作用更为剧烈,颗粒动能转化为切削能,提高了材料的去除率;当颗粒碰撞应力小于材料极限应力时,材料只发生塑性变形,当碰撞应力大于材料极限应力时,才会发生材料去除。试验结果表明:经磨粒流加工的表面粗糙度Ra值由2.03μm降低到0.65μm,研究结果可为后续研究颗粒碰撞和颗粒微切削提供一定借鉴价值。Abrasive flow machining method is a new precision processing method.Unlike the traditonal mechanical processing,the biggest feature of this technology is its polishing liquid.Because of the rheological properties of the polishing liquid,it can enter into any complex and tiny flow channels without limitation.In addition,according to the size and structure of the machined parts,the suitable polishing fluid can be simply and effectively configured.In the abrasive flow machining process,the inlet velocity is the main parameter affecting the processing efficiency and accuracy of the abrasive flow.Therefore,the inlet velocity is selected as the processing parameter to study the processing effect of the abrasive flow on the part.At present,most of the research content about abrasive flow processing is mainly focused on the machine parameters and abrasive configuration,while the particles decisive role in the whole process was ignoring.The essence of abrasive flow processing is the shear,collision,and friction between the innumerable particles and the processed surface,,so it is great significance to study the distribution and mechanical properties of particles.Based on the above background,the micro-component dispensing head is selected as the simulation and test object in this paper.With the abrasive flow machining technology and the combination of CFD(computational fluid dynamics)and DEM(discrete element method),the fluid simulation software FLUENT was used to perform the numerical analysis of the abrasive flow machining process,and the distribution of fluids and particles during processing were discussed,the distribution of fluids and particles under different inlet velocity conditions was compared and analyzed,the micro-cutting behavior of the abrasive flow machining was revealed.The collision model of the particles impact the processed surface was established.The effect of the abrasive flow on processed surface and the material removal mechanism were clarified.Numerical simulations showed that,with the increase of

关 键 词：数值分析 试验 CFD-DEM耦合 磨粒流加工 材料去除 

分 类 号：TH161.1[机械工程—机械制造及自动化] TH117.1