直接蒙特卡罗方法的弯管磨粒流精密加工技术研究

Elbow precision machining technology by abrasive flow based on direct Monte Carlo method

针对弯管类零件内表面精加工技术难题以及磨粒流精密加工弯管中颗粒的作用机制展开了研究。通过结合理论分析、数值和试验的方法进行分析研究。将直接模拟蒙特卡罗方法与有限元分析方法结合揭示磨粒流精密加工过程中颗粒的随机碰撞,在不同的磨粒流入口速度、体积分数以及磨粒粒径下,对弯管中磨粒流的动态压强、湍流动能分析得出了颗粒对壁面的加工机理以及不同加工参数对磨粒流精密加工质量的影响规律。试验结果展示了不同参数对磨粒流精密加工质量的影响顺序并建立了最优工艺参数。讨论了弯管内表面磨粒流精密加工前后的有关表面形态的结果,而且经过磨粒流精密加工后表面粗糙度Ra值由1.125μm降低到了0.295μm。直接模拟蒙特卡罗方法的应用为磨粒流技术的发展提供参考。

The investigation was carried out on the technical problems of finishing the inner surface of elbow parts and the action mechanism of particles in elbow precision machining by abrasive flow.This work was analyzed and researched by combining theory,numerical and experimental methods.The direct simulation Monte Carlo(DSMC)method and the finite element analysis method were combined to reveal the random collision of particles during the precision machining of abrasive flow.Under different inlet velocity,volume fraction and abrasive particle size,the dynamic pressure and turbulence flow energy of abrasive flow in elbow were analyzed,and the machining mechanism of particles on the wall and the influence of different machining parameters on the precision machining quality of abrasive flow were obtained.The test results show the order of the influence of different parameters on the quality of abrasive flow precision machining and establish the optimal process parameters.The results of the surface morphology before and after the precision machining of the inner surface of the elbow are discussed,and the surface roughness Ra value is reduced from 1.125μm to 0.295μm after the precision machining of the abrasive flow.The application of DSMC method provides special insights for the development of abrasive flow technology.