Research On Structure Optimization Of High-Pressure Abrasive Waterjet Excision Nozzle And Characteristics Of Pressurization System

With the rise of new high-quality materials,high pressure abrasive water jet system has been paid more and more attention by more and more enterprises because of its advantages of low cost,no pollution and cold processing,and is widely used in heavy industries such as machinery and metallurgy.However,domestic research on middle and low-pressure water jet has been relatively complete,but for high pressure,especially for the water jet system with pressure above 100 MPa,further research is needed.And the important parts of the high-pressure abrasive water jet system still need to be imported from abroad,our country can independently produce less high-pressure components.Therefore,the study of high-pressure water jet technology is urgent.This paper will study the following aspects:(1)Firstly,the change curves of water velocity and turbulence intensity on the central axis and deviations of the mixing chamber of cutting nozzle were analyzed and drawn,and the optimal abrasive bundling property was obtained by changing the position of the abrasive inlet,and the optimal abrasive inlet position was obtained by combining with the abrasive volume fraction near the inner wall of the mixing chamber.The use of fillet on the rear wall can improve the abrasive trajectory and reduce the corrosion on the rear wall.Transient analysis was used to study the change process from cavity to steady state in the mixing chamber,and the specific time to reach steady state was determined.(2)Secondly,analysis of the abrasive nozzle and the external flow field and the acceleration of abrasive with flow rule,by changing the nozzle structure parameters(Shrinkage Angle and Aspect Ratio)and abrasive particle properties(Abrasive Volume Fraction and Particle Diameter),combined with the abrasive nozzle and the change of the velocity of the abrasive flow and turbulent kinetic energy law of flow field,to optimize the flow of abrasive particles accelerate efficiency,improve the efficiency of cutting nozzle of cutting,to select the optimum parameter value scope.(3)Thirdly,the erosion and wear model of abrasive particles on the inside of the mixing chamber was established,and three parameters(Water Inlet Velocity,Abrasive Mass Flow Rate and Abrasive Particle Diameter)that had great influence on abrasive erosion were obtained through orthogonal test.From the angle of reducing erosion rate,the regularity change of erosion rate is researched,and the suitable value at low erosion rate is calculated.At the same time,the influence of the shape factor on the erosion of the inner wall under the condition of non-spherical abrasive particles was studied(4)Fourthly,the mathematical model of pressure cylinder model is set up based on the principle of pressure cylinder pressurization,pressure flow fluctuation in the high pressure water supply system are analyzed,through AMESim software established hydraulic system,studies the different pressure ratio and the accumulator volume,work,number of cutting nozzle and pressure cylinder for pressure under the effect of the system,build up the volatility and response speed are relatively superior system.