2D伺服阀矩形先导控制阀口气穴特性研究

为研究双自由度（2D）伺服阀先导控制阀口处气穴现象的影响因素及对阀芯稳定性的影响，运用Fluent软件中cavitation模型对2D伺服阀矩形先导阀口进行了气穴特性的仿真研究。研究表明，在出口压力低于1 MPa时，阀口处会出现气穴现象，且因气穴指数σ较小，故在弓形感受通道会出现气泡现象，出口压力高于5 MPa时，无明显气泡现象但阀口处的气穴仍然存在；随着入口流速增加，阀口内侧壁和外侧壁处气穴强度和分布范围增加；在出口压力0.1 MPa情况下，随着阀口开度增加气穴现象减弱。结果表明，2D伺服阀正常工作时先导阀口处会产生气穴，对伺服阀阀芯运动的稳定性产生干扰。

Cavitation Characteristics Research of Rectangular Pilot Control Orifice for 2D Servo Valve

In order to study the influence factors of cavitation at the pilot orifice of two dimensional (2D) servo valve and its influence on stability of valve spool, the cavitation characteristics of rectangular pilot orifice are simulated through the cavitation model in Fluent. The research shows that the cavitation phenomenon occurs at the pilot orifice when the outlet pressure is lower than 1 MPa, and the bubble phenomenon appears in the arcuate flow path because the cavitation index σ is smaller. When the outlet pressure is higher than 5 MPa, there is no obvious bubble phenomenon, however, the cavitation still exists. With the increase of inlet flow velocity, the intensity and the distribution range of cavitation on the medial wall and the lateral wall of orifice are increased. The cavitation phenomenon is weakened with the increase of the orifice opening at the outlet pressure of 0.1 MPa. The results show that the pilot orifice of two dimensional servo valve causes cavitation when it works, resulting in disturbing stability of the servo valve spool movement.