Multi-field Coupling Modeling And Regulation Method Of Gas-liquid-solid Three-phase Abrasive Flow

Gas-liquid-solid three-phase abrasive flow machining is a new super-smooth surface machining method for electronic and information materials with hard and brittle characteristics of the workpiece surface,which uses gas-liquid-solid three-phase swirl abrasive flow in turbulent state.There are some problems in the gas-liquid-solid three-phase abrasive flow machining process: the calculation of flow field distribution in numerical simulation is not accurate,the machined texture is not uniform and the machining efficiency is not high.In this paper,the multi-physics coupling software was used for the multi-field coupling modeling and analysis of gas-liquid-solid three-phase abrasive flow machining process.The numerical simulation results were verified by experiments,and the optimal control method was obtained.The main work of this paper is shown as follows:(1)The problem of ultra-smooth surface machining with electronic and information materials with hard and brittle characteristics of the workpiece surface is taken as the research background.Aiming at the existing deficiencies in the study of gas-liquid-solid three-phase abrasive flow machining,the optimization methods of gas-liquid-solid three-phase abrasive flow machining were proposed.(2)Based on the mechanism analysis of the gas-liquid-solid three-phase abrasive flow machining,the dynamics model of gas-liquid-solid three-phase abrasive flow machining coupled temperature field was established.By comparing the numerical simulation results of coupled temperature field and the uncoupled temperature field,it was found that the former one could obtain the more accurate flow field distribution.On the basis of the coupled temperature field,it was found that the numerical simulation results of the five entrances machining method were better by changing the number of entrances and comparing the flow field distribution.Based on the five entrances machining method,the dynamics model of gas-liquid-solid three-phase abrasive flow coupled ultrasonic field was established.By comparing the numerical simulation results of different ultrasonic fields,it was found that different ultrasonic frequencies and sound pressure amplitudes could bring the different flow field distributions.Among them,the ultrasonic field with the frequency of 20 KHz and the sound pressure amplitude of 30 KPa could obtain the optimal flow field distribution.(3)The experimental platform was built to verify the numerical simulation results.Through the PIV observation experiments,the effect of temperature on the flow field distribution was verified by changing fluid temperature,and the effect of ultrasonic field on the turbulence intensity was verified by changing the parameters of ultrasonic field under the condition of constant fluid temperature.By comparing the machining effects of different entrance machining methods,it was found that the five entrances machining method could get the better machining effect.The machining time was reduced from the original 9h of the three entrances machining method to 4h of the five entrances machining method,and the surface roughness Ra was reduced from the original 0.159?m of the three entrances machining method to 0.125?m of the five entrances machining method.The ultrasonic field was coupled to the machining process on the basis of the five entrance machining method.By comparing with the machining effects of different ultrasonic fields,it was found that the machining effect of the ultrasonic field with the ultrasonic frequency of 20 KHz and the sound pressure amplitude of 30 KPa was the best.The machining time was reduced from the 4h of the five entrances machining method to 3.5h of the coupled ultrasonic field,and the surface roughness Ra was reduced from the 0.125?m of the five entrances machining method to 0.115?m of the coupled ultrasonic field.Moreover,it was found that the coupled ultrasonic field could improve the uniformity of the workpiece surface.