To improve the intershaft seal performance of the dual-rotor turbofan engine and extend the life of the intershaft seal, a compliant cylindrical aerodynamic intershaft seal structure is proposed, which avoids the problem of leakage increase after tooth wear of intershaft labyrinth seal. According to the proposed seal structure, the force condition of the floating seal ring is analyzed, and an aeroelastic coupling method for the floating seal ring eccentricity is presented. And the leakage characteristics, with different seal structures and operating conditions are calculated and compared when the two rotors are under homodromy/counter-rotating condition. The results show that, for the dual-rotor cylindrical hydrodynamic gas film seal, the hydrodynamic effect under homodromy condition is enhanced greatly while the hydrodynamic effect is significantly weakened under counter-rotating condition; the rotational direction of rotors, seal width, rotor circular precession eccentricity, rotational speed and rotor radius all have pronounced influence on the seal performance. For the application of hydrodynamic form of compliant cylindrical intershaft seal, the seal performance under homodromy condition is better than that under counter-rotating condition.

为了提高双转子涡扇发动机轴间密封性能，延长轴间密封寿命，提出一种柔性圆柱气动轴间密封结构，避免了轴间迷宫式密封齿部磨损后泄漏增大的问题。根据所提出的密封结构，分析了浮动密封环的受力情况，提出了浮动密封环偏心的气动弹性耦合方法。计算并比较了两个转子同向/异向旋转时不同密封结构和工况下的泄漏特性。结果表明，对于双转子圆柱流体动力气膜密封，同向条件下流体动力效应大大增强，而异向条件下流体动力效应显着减弱；转子的旋转方向、密封宽度、转子圆周进动偏心率、转速和转子半径都对密封性能有显着影响。对于流体动力形式的柔性圆柱轴间密封的应用，同向工况下的密封性能优于异向工况下的密封性能。