螺旋槽小孔节流动静压空气轴承颗粒冲蚀研究

Study on Particle Erosion of Throttle Hybrid Air Bearing of Spiral Groove

为研究空气轴承在运转过程中细小颗粒对壁面冲蚀情况,借助三维建模工具建立动静压空气轴承模型,从连续方程、可压缩流体润滑方程、气体状态方程出发,推导出等温条件下稳态气体润滑Reynolds方程;结合离散相模型(DPM)颗粒平衡方程,分析颗粒运动轨迹和颗粒对壁面的最大冲蚀速率。借助Fluent仿真软件分析气源压力、主轴转速、粒径参数对气体轴承壁面冲蚀的影响。结果表明:随着粒径尺寸的增加,相同运行工况下,壁面冲蚀磨损速率呈现先增加后降低趋势;随着主轴转速的增加,壁面冲蚀磨损的面积在增加,但最大壁面冲蚀磨损速率在下降,同时壁面磨损面积向主轴正向旋转的方向延伸。

In order to study the wall erosion caused by fine particles during the running of air bearing,a dynamic and static air bearing model was established by means of three-dimensional modeling tool.Based on the continum equation,the compressible fluid lubrication equation and the gas state equation,the steady gas lubrication Reynolds equation at isothermal condition was obtained.Combining with the discrete phase model(DPM)particle balance equation,the trajectory of particle motion and the maximum erosion rate of particles on the wall were analyzed.With the help of Fluent simulation software,the influence of gas pressure,spindle speed and particle size on the wall erosion of gas bearing was analyzed.The results show that with the increase of particle size,the wall erosion wear rate increases first and then decreases under the same operating conditions.The area of wall erosion wear increases with the increase of spindle speed,however,the maximum wall erosion wear rate is decreasing,and the wall wear area extends to the direction of spindle rotation.