极端服役环境下航空发动机双转子系统瞬态动力学理论与实验

Military aeroengines not only have complex structures (with dual-rotor or tri-rotor) and high operational parameters (high rotating speed, high temperature, and high pressure), but also endure extreme service environments. In such extreme service environments, the aeroengines work with high rotating speed/acceleration, high maneuver acceleration, or many combination of over loads and maneuvers. So a lot of faults such as rub, blade break, losing stability, stop, even fire or disastrous accident will happen. Most of the current researches concern models of dual-rotor without maneuvers or single-rotor with maneuvers and the steady responses of the model. Until now, little research concerns transient responses of dual-rotor models with maneuvers, and many studies discuss steady responses of single rotor models without maneuvers. However, transient dynamics of dual-rotors under extreme service environments are still need to be investigated. For this reason, this project will consider the extreme service environments (complex maneuvers, variable rotating speeds, etc), and study transient responses of aeroengine dual-rotor systems. Furthermore, typical faults induced by extreme service environments are to be investigated through relationships within dynamic responses, fault characters and service environments. Moreover, related experiments are to be carried out through the improvement of the existing dual-rotor test rig of the research group. Finally, these studies would not only promote the theoretical research of aeroengine dual-rotor dynamics but also guide the design, operation and maintenance of aeroengines.

航空发动机不仅结构复杂（套装双或三转子）、运行参数高（高转速、高温、高压），还存在着极端服役环境（对军机）。在极端服役环境下，航空发动机不仅存在高转速/加速度，还存在高机动飞行加速度，并且常常包含多个极限过载和机动组合，因此极易发生碰摩、叶片断裂、失稳、停车等故障，甚至导致起火或机毁人亡的重大事故。现有文献大多针对不考虑机动飞行的双转子或考虑机动飞行的单转子开展研究，且主要分析稳态响应，尚未对考虑极端服役环境下的双转子瞬态动力学特性开展系统研究。为此，本项目拟考虑机动组合、变转速等极端服役条件，开展航空发动机双转子系统瞬态动力学研究，针对极端服役环境导致的转子失稳和故障传递开展机理分析，获得服役条件与动力学响应、故障特征之间的关系，并通过改造课题组已有的机动飞行双转子实验台，开展相应的实验研究。本项目成果不仅能够丰富航空发动机双转子动力学理论，还可为发动机设计、运行与维护提供理论指导。

极端服役环境下航空发动机不仅存在高转速/加速度，还承受高机动飞行载荷，因此容易发生转子系统运行失稳与振动故障加剧等现象，从而引发发动机损坏、熄火等，严重时可导致机毁人亡。本项目以机动飞行环境下航空发动机双转子系统动力学建模和瞬态响应分析研究为主线，从理论和实验研究两方面对系统振动响应和运动稳定性开展了研究，并分析系统在机动飞行环境下的典型故障机理。首先，建立了机动飞行条件下复杂结构支撑-非对称转子系统的动力学模型，模型考虑了滚动轴承和挤压油膜阻尼器耦合非线性支承作用力，研究了机动载荷作用下转子系统的双稳态现象、振幅跳跃行为和非同步振动等非线性响应，给出了转子运行失稳的临界飞行参数。其次，考虑了机动飞行环境下双转子系统的中介轴承损伤故障，研究了系统参数（包含转子参数与飞行参数）对双转子冲击振动响应及轴承接触力脉冲的影响规律，阐明了瞬态机动载荷作用对转子系统响应的调幅调频作用机理。再次，研究了瞬态机动载荷引发的转子系统碰摩响应，揭示了碰摩后转子系统弯扭耦合振动规律，给出了弯曲振动和扭转振动时频特征的区别与联系；然后进一步研究了不对中-碰摩耦合故障转子系统的振动响应特征，分析了机动飞行下碰摩故障转子系统和耦合碰摩故障转子系统振动的内在联系与区别。最后，搭建了能模拟复杂机动飞行条件下典型故障转子实验台，开展了各种典型故障转子瞬态响应实验研究，分析了实验结果响应的时频域特征，验证了理论模型的正确性。项目研究成果可为机动飞行环境下航空发动机动力学设计与振动故障诊断提供理论指导。