转/静子齿对迷宫密封泄漏特性与动力特性影响机制研究

Research on Influence Mechanism of Rotor/Stator Teeth on Leakage and Dynamic Characteristics of Labyrinth Seal

迷宫密封齿设计于转子或静子上对迷宫密封的性能影响较大。为揭示转/静子齿对迷宫密封泄漏特性与动力特性的影响机制,应用非定常动网格技术建立了迷宫密封泄漏特性与动力特性多频椭圆涡动求解模型,在验证求解模型准确性基础上,分析转/静子齿迷宫密封的泄漏特性与动力特性,并讨论2种结构对迷宫密封转子系统稳定性的影响。结果表明:转/静子齿迷宫密封的泄漏量均随压比的增加而增大,在12000~24000 r/min转速下,随转速的增加而减小,且转子齿迷宫密封的泄漏量始终高于静子齿迷宫密封;影响转/静子齿迷宫密封泄漏量的因素为泄漏面积;与转子齿迷宫密封相比,静子齿迷宫密封有着较大的有效刚度与有效阻尼,二者的切向气流力与转子涡动方向相反,均抑制了转子的涡动,且静子齿迷宫密封的切向气流力大于转子齿迷宫密封,因此静子齿迷宫密封更有利于转子系统的稳定性。

The design of the labyrinth seal teeth on the rotor or stator has a great influence on the performance of the labyrinth seal.In order to reveal the influence mechanism of the rotor/stator teeth on the leakage and dynamic characteristics of the labyrinth seal,a multi-frequency elliptical vortex solution model for the leakage characteristics and dynamic characteristics of the labyrinth seal was established by using the unsteady dynamic grid technology.On the basis of verifying the accuracy of the solution model,the leakage characteristics and dynamic characteristics of the rotor/stator teeth labyrinth seal was analyzed,and the effects of the two structures on the stability of labyrinth seal rotor system were discussed.The results show that the leakage of the labyrinth seals of rotor/stator teeth increases with the increase of pressure ratio,and decreases with the increase of speed at the range from 12000 r/min to 24000 r/min.The leakage of the lrotor teeth labyrinth seal is always higher than that of the stator teeth labyrinth seal.The factor affecting the leakage of rotor/stator teeth labyrinth seal is the leakage area.Compared with the rotor teeth labyrinth seal,the stator teeth labyrinth seal has greater effective stiffness and effective damping.The tangential airflow force of the rotor/stator teeth labyrinth seal is opposite to the direction of the rotor whirl,both can suppress the whirl of the rotor.The tangential airflow force of the stator teeth labyrinth seal is greater than that of the rotor teeth labyrinth seal.Therefore,the stator teeth labyrinth seal is more conducive to the stability of the rotor system.