Numerical Simulation And Experimental Study On Material Removal Of Wet Spindle Mass Finishing

Material removal rate is an important evaluation index for the processing effect of mass finishing,which is able to predict surface quality and performance parameters of the workpiece.And wet mass finishing is the most commonly used mass finishing in the precision equipment production.The liquid medium has a significant influence on the flow field morphology of the processing medium,so computational fluid dynamics is introduced into computational analysis of medium flow field in processing.In the wet mass finishing,the lack of integrity and systematic research on the material removal mechanism is carried out using the computational fluid dynamics software FLUENT to simulate the pressure difference and velocity field affecting the material removal mechanism.And a suitable material removal model for wet spindle mass finishing was constructed based on the Preston equation,which is helpful considering the surface quality requirements of the workpiece for reasonable choice process parameters.The main research contents are as follows:?1?The basic principles,solution process and basic control equations of fluid dynamics were analyzed.And based on the two-phase flow module of FLUENT software,it select the calculation model suitable for wet spindle mass finishing:standard k-?two equations turbulence model and mixture multiphase flow model.?2?Based on mixture model,standard k-?turbulence model and pressure-velocity coupled SIMPLEC algorithm,numerical simulation was performed for the solid-liquid two-phase turbulent flow composed by the medium flow field in spindle mass finishing.The distribution of media velocity vector and workpiece surface pressure under different parameters was analyzed by changing the process parameters like barrel speed,distance from workpiece axis to the barrel wall.The effectiveness of the simulation was verified by test experiments.In the initial simulation,the maximum point of static pressure was32 MPa at 0°,the maximum point of dynamic pressure was about 35 MPa at 90°and 270°,and the total pressure in the wake area was greatly reduced to 33%at0°.The part on the workpiece facing media is subject to impact and compression,while two sides are subject to scratching effect.In the analysis of the process parameters,when the rotating speed is 100 r/min,the distance between the workpiece axis and the wall is 65 mm,and the proportion of media in the processing medium is 70%,the total pressure of the workpiece surface is the largest.And media has the strongest processing capability for the workpiece.The pressure average error of numerical simulation and experimental results is5.25%,which proves the validity of the simulation.?3?The experimental platform of wet spindle mass finishing and the test platform of surface quality and material removal rate is used for the single factor analysis of the process parameters in the process,the results show that:when the rotating speed of 50r/min⁹0r/min,the distance between the workpiece axis and the wall is 90mm¹30mm,the diameter of media is 3mm⁷mm,and the range of media in the processing medium is 50%⁷0%,the surface of the workpiece has a high rate of decrease in Ra and Rz values.And the surface quality of the workpiece is no longer significantly improved after 20 minutes of processing.The MR of the workpiece is approximately proportional to the time.And when the rotating speed is 90r/min,the distance between the workpiece axis and the wall is 90mm,the diameter of media is 10mm,and the proportion of media in the processing medium is 70%,the MRR reaches a maximum.?4?The FLUENT two-phase flow module is used to simulate the p·v value under different parameters,and the response surface method is used to fit the multiple regression model of four main parameters and p·v.A modified material removal model is established based on the Preston equation.Perform processing experiments to investigate the relationship between MRR,Ra after processing and surface topography of the workpiece.P value of the workpiece axial distance from the wall and the drum speed term which has a significant influence on MRR is<0.05 in the analysis of variance.The model experiments were verified that the average relative error of workpiece's MRR_thh and MRR_exx was only 6.32%,which proved the validity of the model.With the increase of MRR,Ra after processing is from reduced to increased.MRR is 21mg/h.Ra is0.816?m.And the knife is still very obvious;MRR value is 59mg/h.The lowest value of Ra is 0.472?m.And the knife is completely removed.The surface texture is smooth and the processing effect is best;When MRR reaches the extreme value,Ra is 0.693?m,the surface texture becomes rough and uneven,and the processing effect is poor due to excessive processing ability of the media.A material removal model with process parameters as independent variables is established to provide a theoretical basis for selecting parameters;and experimental research shows that there is no positive correlation between processing capacity and effect.