提出贯通式与间隔式两种新型逆滞流迷宫密封结构，通过在密封齿上设计微型逆滞喷管，贯通相邻密封腔，利用自然压差产生逆向射流，产生滞止效应，抑制密封腔内周向流动。应用基于微元理论的密封动力特性系数识别方法研究两种逆滞喷管密封动力特性，并与传统迷宫密封进行对比。研究表明：逆滞流迷宫密封产生的反旋流对抑制密封腔内周向流动具有较好的效果；间隔式较贯通式逆滞流迷宫密封具有更高的稳定性，高涡动频率下有效阻尼可达原结构的200%；逆滞喷管的布置增加了原结构密封的泄漏量，但可通过调节周向逆滞喷管数量，满足机组对稳定性需求的同时具有相对较低的泄漏量。

The through and interval type of an antistagnant labyrinth seal were proposed to generate opposed jet,suppressing the circumferential flow in the seal cavity by pressuredriven micronozzles on the adjacent seal tooth.The identification method using the infinitesimal method was applied to predict rotordynamic coefficients of annular gas seals.The dynamic characteristics of two types of antistagnant labyrinth seals were calculated.The new structure was compared with that of the traditional labyrinth seal.The reverse swirl produced by the antistagnant labyrinth seal has better effects on restraining circumferential flow in the seal cavity.The new structure has better stability with the effective damping coefficient 200% of the original structure at high whirling frequency.The leakage of the antistagnant labyrinth seal is slightly higher than that of the original structure,but it can obtain the stability with relatively low leakage flowrate by adjusting the circumferential number of the antistagnant nozzles.

TK14

国家自然科学基金（51875361，51676131，51575105