基于RNGk-ε模型的大曲率弯管的软性磨粒流加工仿真与实验  

Soft Abrasive Flow Machining Simulation and Experiment of the Large Curvature Bend Based on RNG k-ε Model

作　　者：沈明[1] 戴勇[1] 褚聪[1] 叶见领 葛满 袁巧玲[1] 

机构地区：[1]浙江工业大学,浙江杭州310014

出　　处：《液压气动与密封》2016年第5期39-44,共6页Hydraulics Pneumatics & Seals

基　　金：国家自然科学基金(50875242)

摘　　要：针对微小尺寸、大曲率弯管结构化内表面难以使用工具进行接触式光整加工的问题。该项目提出了一种使用软性磨粒流加工此种类型弯管内表面的方法。为了验证理论分析的正确性,基于RNG k-ε湍流模型对加工过程中整个流道内部进行仿真实验。并搭建了实验平台进行加工实验,以验证仿真结果的可靠性。仿真的结果表明,磨粒在弯管内处于无规则的运动状态,并且弯管内部的内、外两侧壁面存在着明显的速度差和压力差,并且随着入口压力从2.0MPa增大至3.0MPa,内部压力与速度也随之增大。在加工实验中,对工件进行加工前,工件内表面各点粗糙度都相对较大,因此平均粗糙度也相应较大,大约为1.072μm。工件加工一段时间后,整个内表面的光整度变好,而且伴随着入口压力的增大,加工效果变好,表面粗糙的均匀程度提高,光整性也逐渐提高,可达0.450μm。加工实验结果证明磨粒在近壁区的切削痕迹确实呈无序化的运动形态,与前期的数值仿真结果相吻合。理论分析,仿真实验与加工实验共同为软性磨粒流实现微小尺寸、大曲率弯管的无工具精密加工提供了理论和现实依据。In view of the problems of surface of small size and large curvature bend structural is difficult to use tools to make the contact skin pass processing. This project presents a method to use soft abrasive flow to process this type of the inner surface of elbow pipe. In order to verify the theoretical analysis is correct, to do simulation experiment in the whole inside of flow passage during the process of processing based on RNG k-e turbulence model. Also, the experimental platform is built to do processing experiment In order to verify the reliability of the simulation experiment. The results of simulation show that the wear particles are doing irregular movement in the elbow pipe, and there are obviously velocity and pressure differences in the inner and outer wall of the elbow pipe. And with the inlet pressure increased from2.0MPa to 3.0MPa, the internal pressure and speed will also increase. In processing experiment,each point of internal surface of the workpiece is relatively large before processing, so average roughness is correspondingly larger, about 1.072μm. After the workpiece is processed for a period of time, the light of internal surface becomes better, and with the increase of the entry pressure, the effect of processing gets better, the average level of surface roughness is increased and the light is gradually improved, up to 0.450μm. The results of processing experiment show that the cutting marks in the near wall region of the wear debris is indeed doing the irregular movement, which is fit with the results of the numerical simulation in early stage. Based on the theoretical analysis that simulation experiments and processing tests provides a theoretical and practical evidences for soft abrasive to achieve a small size and precision machining without tool of large curvature bend.

关 键 词：小尺寸 大曲率 结构化内表面 软性磨粒流 RNG k-ε湍流模型 无工具精密加工 

分 类 号：TH137[机械工程—机械制造及自动化] TG664[金属学及工艺—金属切削加工及机床]