基于CFD的伺服滑阀冲蚀磨损特性分析

目的研究颗粒杂质对伺服阀污染磨损的特点及规律,为提高伺服阀使用寿命提供参考意见。方法将计算流体力学与冲蚀理论相结合,建立伺服滑阀流场的冲蚀模型,对滑阀的冲蚀磨损情况进行可视化仿真。结果冲蚀磨损最严重的部位发生在阀口控制面锐缘,且沉割槽端面锐缘的磨损速率明显大于凸肩侧面锐缘。阀口的磨损速率与颗粒浓度基本成线性关系,且正相关,而随着阀口开度的增大,沉割槽和凸肩控制面锐缘的磨损速率均降低。质量流率不变时,阀口磨损速率整体上随颗粒直径的增大而增大,并对某一直径颗粒较敏感,且随着阀口开度的增大,所对应的敏感颗粒的直径也逐渐增大。结论应对阀口部位进行工艺处理,以增强其耐磨性。滑阀多处于大开口度下工作,可一定程度上减轻磨损。大直径颗粒对滑阀磨损更严重,在油液净化过程中应当严格控制。

CFD-based Characteristic Analysis of Erosion Wear of Servo Slide Valve

The work aims to provide suggestions for expanding service life of servo spool valve by studying characteristics and law of contaminant wear to servo spool valve by particle impurities. By combining computational fluid mechanics (CFD) with erosion theory, the erosion model of servo spool valve flow field was built to simulate the erosion wear of servo spool valve. Sharp-edge of valve port''s controll surface was seriously damaged by erosion wear, and wear rate of the sharp-edge of groove was clearly higher than that of the sharp-edge of shoulder. The relation between the wear rate of valve port and the particle concentration was linear and positively correlated, yet both the wear rates of the sharp-edges of groove and shoulder reduced as the opening of valve port increased. When the mass flow rate was constant, the erosion rate of valve port increased as a whole as the diameter increased. The valve port was more sensitive to one particle of certain diameter. As the opening of valve port increased, the diameter of particle to which the valve port was sensitive increased as well. In order to improve the wear resistance, the valve port shall be reprocessed by fabrication processing. To a certain extent, the erosion rate declines if the spool valve works at big opening. The wear caused by particles of large diameter is severer and should be controlled strictly during oil purification.