| The study of polishing process on inner surface of tubing has been the focus and difficulties at home and abroad,The traditional polishing methods with general tools is hard to realize its processing on the inner surface of workpiece because of its structural characteristics,And the surface of workpiece will experience machining damage in different extent and the quality of processing is uneven after be polished,Polishing quality is difficult to meet requirements of actual processing.For the difficult problem of inner surface of tubing polishing processing,the polish methods of spiral bound abrasive flow is brought forward in this paper.A restricted passage is formed by configure a restricted module in combination with the inner surface,The polishing machining based on the low-strength low-speed cutting by abrasive grain can realize the processing of inner surface of workpiece.The main work and conclusions are described as follows:(1)Based on the basic theory of dynamics of particles and solid-liquid two-phase flow,the basic physical model of spiral bound abrasive flow was established,RNG k-? model and mixture model has been chosen as turbulence model and multiphase flow model in this paper.(2)An polishing device was designed by the analysis of characteristics of the polish methods of spiral bound abrasive flow,And the key parts of device was analyzed,the overall structure can meet the requirements of strength and stiffness by the finite element analysis of the key part of device,and it can realize such kind of processing with safe,stable and high efficiency.(3)Based on the theory of erosion wear of particle,A finite element model for single-particle impacting was established by using ANSYS/LS-DYNA,And to provide a theory for the further analysis of the mechanism of material removal through the study of the properties of impact wear,the simulation results show that initial impact occurred mainly as elastic-plastic deformation,it begin to appear the wear of material after several impacting,it will increase the amount of material removal with the increase of impact velocity and the number of impacting.(4)Based on the RNG k-? model and Mixture model,the flow characteristics of restricted passage was analyzed by FLUENT,the simulation results show that flow field in the flow passage has reached turbulent state when keep the restricted module still,it is good for uniform processing because the distribution of velocity field,pressure field and turbulent kinetic energy is relatively uniform,the flow rate was increased gradually when increase the rotating speed of restricted module,it also can strengthen the scraping action of particles on the surface of workpiece,and effectively improve the processing efficiency.(5)Studying the characteristics of flow field in spiral groove based on particle image velocimetry(PIV)system,And it have obtain the characteristics of velocity field and vorticity,the motion characteristics of particle was obtained by the use of high-speed camera to observe the motion status of particle in the whole flow passage,And it verify the correctness of simulation results.(6)Based on simulation results of flow field and observations experiment,putting up the experimental platform for polish methods of spiral bound abrasive flow,the experimental results shows that the quality of the surface of workpiece is improved based on low-strength low-speed cutting by the abrasive grain when keep the restricted module still,the rough surface becomes smooth when increase the rotating speed of restricted module,and the removed quantity of material was increased gradually,the efficiency of processing was also improved with the high rotating speed of restricted module,the processing experiments indeed prove the feasibility and high efficiency of the polish method of spiral bound abrasive flow. |
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