Vibration Performance Of Rotor System With SFD In Maneuver Flight

Maneuverability is one of the most important tactical and technical performances for fighter planes. The greater the maneuver load planes can endure, the better their maneuverability is. However, the maneuver flight would change the load acted on the aero-engines and then affect its vibration characteristics. Nowadays, squeeze film dampers (SFD) are used to reduce the vibration in many aero-engines, and then their performance in maneuver flight will affect the whole engine. In order to ensure the stable work of fighter planes while increasing their maneuverability, it is necessary to investigate the vibration performance of aero-engine in maneuver flight.This dissertation aims to reveal the influence of maneuver load (including additional centrifugal force and gyroscopic moment) on the vibration performance of rotors with SFD.First, the angular velocity function and maneuver load for certain maneuver flight (including hover, dive-hike and these two combined) are set up. The simulation results of the vibration of double-disk rotor system with cantilever supported on rigid bearings show that rotor would be apparently deformed under maneuver load. Second, the performance of oil force of SFD in maneuver flight is analyzed. The results show that in maneuver flight, the SFD with centering spring will become eccentric and its oil force will be time-related and offset-related. Then, SFDs are introduced into typical Jeffcott rotor system. The whole system will be statically displaced in maneuver flight and the nonsynchronous components of oil force appear in the response of rotor system. Finally, the influences of system configuration parameters and work condition parameters on the vibration performance of rotor system are simulated and analyzed. At the end, the vibration responses are displayed in polar diagram synthetically, in which the displacement, the static offset and the deflection angle of rotor could be shown altogether.It is concluded that the influences of maneuver flight on the rotor system of an aero-engine are evident, therefore, they should be taken into account during design of the engine.