Response Analysis And Study On Aero-engine Dual-rotor System Under Random Excitation

Aero-engine is the heart of aircraft, and rotor system is the core component ofaero-engine. So it needs to fully understand that possible vibration response ofaero-engine rotor system working at high altitude before designing the structure ofaero-engine rotor system, in order to take corresponding measures of vibration controlto prevent flight accidents. Over the years, the researches of engine vibration of rotorsystem mainly focused on vibration response caused by internal cause of system, suchas the rotor imbalance, rotor misalignment etc, while the vibration response caused bysystem external incentives was rarely discussed. Atmospheric turbulence, as ansignificant external incentive, has the remarkable random characteristics asaero-engine rotor system working at high altitude. The aero-engine rotor systemdynamic response under atmospheric turbulence incentive is a complex randomprocess, so it is very important to study dynamic response of aero-engine rotor systemunder random incentive of atmospheric turbulence that the theory basis to designvibration control structure for aero-engine research personnel can be provided.In this paper, the apply and research situation of aero-engine dual-rotor systemare firstly introduced; domestic and overseas theory achievements of wing vibrationresearch are explained, and the application in random vibration of pseudo-excitationmethod is reviewed. Secondly, the theory of rotor dynamics and wing pneumaticelastic mechanics are introduced in detail, and several basic principles of atmosphericturbulence model and pseudo-excitation method are given. Dryden turbulence modelwas adopted as the atmospheric speed model according to the atmospheric effects ofaero-engine, motion equations of wing-mounted aero-engine dual-rotor system underrandom incentive of atmospheric turbulence was established. Finally, the dynamicresponses of imbalance at various working conditions are discussed by numericalexample and the dynamic responses of dual-rotor system at atmospheric turbulencerandom excitation are solved by using pseudo-excitation method. The results showthat displacement response of various turntable stations of dual-rotor system will varywhen the system is subject to additional excitation. Variation trends for the powerspectral density (PSD) of displacement response of various turntables station in the rotor system are almost identical with the PSD of atmospheric turbulence speed.However, due to the characteristics of rotor system itself, displacement responseintensity cymomotive occurs at natural frequency. The displacement response intensitycaused by atmospheric turbulence is particularly evident when angular frequencyat0~10rad/s.