Numerical Simulation And Experimental Study On Airless Spraying Of High-speed Rail

With the rapid development of China’s high-speed railway industry,the operation quantity of high-speed railway has increased sharply,which puts forward higher requirements for the manufacturing technology of high-speed railway manufacturing industry.The produced high-speed railway requires stable quality and green production process.Nowadays,the surface coating of high-speed railway body has basically realized automation,but the coating of atomic gray coating of car body still uses manual scraping,which has high operation technology for workers,The work intensity of workers is high,and the component of atomic ash contains organic solvents harmful to the environment and human body.In this paper,the spraying method is proposed to operate the car body atomic ash coating.According to the atomic ash thick paste spraying liquid and the thickness requirements and coating environment of high-speed iron atomic ash coating,the fluid simulation method is used to analyze the car body atomic ash spraying process.This paper analyzes the scraping process and working conditions of traditional atomic ash coating,determines the atomic ash spraying scheme,and finally determines to operate the atomic ash coating of high-speed railway car body by high-pressure airless spraying,designs the high-pressure airless atomic ash spraying device,takes the GG0 standard airless nozzle as the spraying simulation object,and uses commercial CFD software to simulate the pressure and velocity distribution of atomic ash spraying liquid in the internal flow field of airless nozzle,The effects of spray pressure and coating viscosity on spray flow were analyzed.The discrete phase model(DPM)was used to simulate the spray characteristics of atomic ash spray solution.The wall film model was used to simulate the spray film formation of atomic ash coating,and the thickness distribution of high-pressure airless atomic ash coating was simulated.The atomic ash spraying experimental platform is built,and the three-dimensional coating thickness distribution model is established.The coating thickness curve is fitted with the experimental data by using the data processing software.The optimal overlapping rate is determined to be between 30% and 35% by comparing the experimental and simulated coating thickness distribution.The variation of coating utilization rate with pressure is analyzed,and finally the adhesion grade of airless spraying atomic ash coating is determined through the experiment,The research results of this paper can provide data reference and theoretical guidance for the spraying of atomic gray coating on high-speed railway body.