In order to investigate the effect of abrasive flow on the polishing effect of variable diameter pipe parts, taking the fourth-order variable-diameter pipe part as the research object, the solid-liquid two-phase abrasive grains are used as the processing method of the fourth-order variable-diameter pipe, the numerical simulation of the machining process of the four-order variable-diameter pipe parts were carried out. Analysis of different inlet speed conditions, the dynamic pressure and the distribution of turbulence intensity of the flow field of the fourth order variable diameter pipe. Through comparative analysis, the effects of the four-stage variable-diameter pipe flow field are studied, which can provide the theoretical basis for the continuous improvement of the abrasive flow precision and ultra precision machining technology, which can improve the efficiency of abrasive flow processing, so that the workpiece fatigue strength is improved, enhance the reliability of the workpiece, extend the service life of the workpiece.

Abstract. As a kind of nano machining technology, abrasive flow polishing technology plays an important role in precision machining region. As an important numerical simulation method in fluid mechanics, large eddy numerical simulation method has become an important method for many scholars to study abrasive grain polishing technology. In this paper, the use of fluid mechanics software FLUENT and selected Mixture mixed model. Based on the theory of solid-liquid two-phase flow dynamics, the large-eddy numerical simulation method was used to study the polishing process of T-tube abrasive flow, and the micro-machining mechanism of abrasive-polished workpiece was discussed. The influence of the different inlet velocities on the polishing effect of the abrasive grains was discussed by analyzing the numerical simulation results of the different inlet velocities of the abrasive grains during the processing of the T-tube.

Abstract. Abrasive flow machining has become an efficient and economical ultra precision process for machining micro-bore parts. In this paper, aiming at viscosity temperature characteristics of abrasive flow finishing on micro-bore nozzle, under the guidance of the three governing equations of fluid mechanics theory, mixed phase model and discrete phase model were conducted, FLUENT software was resorted to simulate the discrete and fluid phase numerical characteristics of the solid-liquid two-phase flow field in the nozzle orifice with various field temperature and viscosity of slurry, the mechanism of erosion and wear of particles and effect of different processing parameters on particle erosion rate were uncovered, which provides a theoretical basis for the nozzle structure of abrasive flow machining.

Abstract. In the fields of aerospace, precision machinery and energy, there are variable-diameter tubes for many key components. Abrasive flow polishing technology is an effective precision polishing technology for finishing the workpiece with an internal cavity structure. This technology can improve the quality of part finishing, reduce stress concentration, and reduce the surface roughness of the workpiece, and ultimately can improve the performance of the workpiece. In this paper, variable-aperture tube is taken as the research object, and the characteristics of abrasive flow in the multi-physics coupling field are studied by numerical simulation, and the collision removal effect between the abrasive particle and the wall surface is analyzed. We also discussed the control law of the abrasive grain flow processing quality and provided theoretical guidance for abrasive grain flow polishing of this type of part.