喷丸过程中喷嘴移速对颗粒分布的影响

目的探究喷丸过程中颗粒在靶材上的分布特性及喷嘴移动速度带来的影响。方法利用FLUENT对定点喷丸过程进行CFD仿真,获得定点喷打时颗粒在靶材上的位置,然后再使用MATLAB对定点喷打的颗粒结果进行叠加处理,以此模拟连续喷丸过程。首先进行平面喷打模拟,分析喷嘴速度对颗粒分布的影响。通过添加颗粒查询方法可对旋转喷丸过程进行模拟,以方型柱体为例进行转动喷打,并优化转动速度。结果喷嘴匀速平移时,在喷嘴路径方向上的颗粒分布密度恒定,该密度值与移动速度呈反比;变速平移时,在喷嘴路径方向上的颗粒分布密度与喷嘴扫掠截面和喷嘴移动速度相关,且喷嘴扫掠截面越小,颗粒分布密度与运动速度越接近反比,并利用数学模型验证了方法的可靠性;旋转喷打时,针对方型柱体靶材,匀速转动喷打的颗粒分布密度呈起伏变化,通过优化转动速度得到大幅改善,可节约24.2%的喷丸时间与颗粒使用量。结论采用FLUENT与MATLAB结合的方式,可对连续喷丸过程中靶材上的颗粒分布进行合理描述。匀速平移喷打时,颗粒分布密度与移速呈反比;变速平移喷打时,颗粒分布密度与移速呈负相关,靠近反比关系;变速转动喷打时,合理的变速转动喷打较匀速转动喷打拥有更好的颗粒分布均匀度,可大幅缩减颗粒使用量,并提高喷丸效率与喷丸质量。

Effect of Nozzle Moving Speed on Particle Distribution During Shot Peening

The paper aims to investigate the distribution characteristics of particles on the target during shot peening and the influence of nozzle moving speed. The CFD simulation of the fixed-point shot peening process was performed with FLUENT to obtain the position of the particles on the target during the fixed-point shot peening; and then the results of the fixed-point shot peening were superimposed with MATLAB to simulate the continuous shot peening. Plane shot peening simulation was conducted to analyze the impact of nozzle speed on particle distribution. The particle tracing method can be used to simulate the rotating shot peening process with a square cylinder as an example to perform rotating shot and optimize the rotating speed. When the nozzle was moved at a constant speed, the particle distribution density in the direction of the nozzle path was constant, and the density value was inversely proportional to the moving speed. During variable speed translation, the particle distribution density in the direction of the nozzle path was related to the nozzle scanning section and the nozzle moving speed. The smaller the nozzle sweep cross section, the closer the particle distribution density was to the inverse ratio of the moving speed, and the mathematical model was used to verify the reliability of the method. In rotary shot spraying, the particle distribution density of the constant rotating spraying target for a rectangular cylindrical target showed fluctuation, which can be greatly improved by optimizing the rotation speed. 24.2% of the shot blasting time and the amount of particles used can be saved. The combination of FLUENT and MATLAB can reasonably describe the particle distribution on the target during continuous shot peening. When the shot is shifted at a constant speed, the particle distribution density is inversely proportional to the speed of the shot. The speed of movement is negatively correlated, close to an inverse relationship; in variable-speed rotary blasting, reasonable variable-speed rotary blasting has better particle distribution uniformity than constant-speed rotary blasting. It can greatly reduce the amount of particles used, and improve the shot peening efficiency and shot peening quality.