干气密封滑动密封端面高频微幅摩擦振动研究

为揭示干气密封端面间摩擦振动规律,通过对密封端面在干摩擦状态下的微观形貌与受力进行分析,基于分形理论构建包含分形参数的密封端面法向位移激励,以及干气密封在干摩擦状态下的两自由度摩擦振动系统模型,并对摩擦振动系统模型的影响因素进行数值分析。研究结果表明:法向振动位移和速度随着分形维数与转速的增大先增大后减小;密封环面分形维数在1.3左右,以及密封环面平均滑动速度为67.86 m/s时会导致密封端面在法向出现共振现象;法向振动位移和速度随着特征尺度与摩擦因数的增大而增大;法向振动以准周期的高频微幅振动规律变化,相比于特征尺度,分形维数对法向振动的影响更加显著,而摩擦因数对法向振动来说不是一个敏感因素;切向振动位移和速度随着摩擦因数的增大而增大,而且以周期性的高频微幅振动规律变化;摩擦因数对系统切向振动的影响比对法向振动的影响更加明显。

Research on High-Frequency and Micro-Amplitude Friction Vibration of Sliding Seal Face in Dry Gas Seal

In order to reveal the frictional vibration law between end faces in dry gas seals,the microstructure and stress of seal face were analyzed under dry friction condition.Based on fractal theory,the normal displacement excitation of seal face with fractal parameters and a two degree of freedom friction vibration system model of dry gas seal in dry friction state were constructed.The influence factors of the friction vibration system model were analyzed numerically.The results show that the normal vibration displacement and velocity are increased first and then decreased with the increase of fractal dimension and rotation speed.When the fractal dimension of the sealing ring surface is about 1.3 and the average sliding speed of the sealing ring surface is 67.86 m/s,the resonant phenomenon of seal face in normal direction will occur.The displacement and velocity of normal vibration are increased with the increase of characteristic scale and friction coefficient.The normal vibration changes with quasi periodic high frequency and micro amplitude vibration law.Compared with the characteristic scale,the fractal dimension has a more significant influence on the normal vibration,while the friction coefficient is not a sensitive factor for the normal vibration.The tangential vibration displacement and velocity are increased with the increase of friction coefficient,and change periodically with high frequency and micro amplitude vibration.The influence of friction coefficient on tangential vibration is more obvious than that on normal vibration.