Research On Aero-engine Rotor Vibration Based On Magnetorheological Damper

Aero-engine,as an important power system of aircraft,it’s working state will directly affect the safety of the aircraft.The unbalanced vibration of the engine rotor is the main threat of aero engines,and the control of the rotor vibration is very important.Vibration damper is a common technique method for rotor vibration control.Magnetorheological fluid(MRF)damper is a new type of active damping device.It has been widely used in automobiles,constructions and other vibration control fields due to its precise control,low power consumption,and continuously adjustable damping force.According to the vibration characteristics and working conditions of aero-engine rotor,a shear magnetorheological damper is designed in this paper,a single-span rotor vibration model is established,and three control methods are studied.Firstly,modeling and analyzing the main characteristics of high-and low-pressure rotor vibration of aero-engine and the actual working environment of the rotor.The vibration characteristics are summarized,and determining the simplified direction of simulation.Then,based on the magnetorheological damper researched by the predecessors,combined with the actual working state and vibration characteristics of the aero-engine,a shear-type magnetorheological damper with squirrel cage structure was designed.With the basic knowledge of nonlinear dynamics theory,magnetorheological fluid theory and magnetorheological fluid damper design,the dimensional structure of the damper is analyzed,and the structure of the magnetorheological damper is analyzed by the ANSYS APDL.The size is optimized to make the structure more reasonable.Secondly,a damper-single-span rotor simulation model is established in Simulink by establishing the damper-rotor dynamic equation,and the damping effect of the damper is simulated.Finally,based on the simulation model,the current switch control and current segment control based on speed are studied,and closed-loop feedback control based on speed and amplitude control is proposed.The advantages and disadvantages of the three control methods are analyzed.Then apply different current to different speed range to make the rotor pass through the critical speed range smoothly.The results show that the structure size of the squirrel cage structure shear MR damper is reasonable,the utilization rate of magnetic circuit is high,it can output large damping force,the damping is adjustable,the working mode is more in line with the vibration characteristics of the aero-engine rotor,and it has good damping effect.The vibration amplitude of the rotor can be reduced obviously by applying different current in different speed range comparing to the SFD,and the rotor system can work smoothly Through the critical speed region,it provides a reference for the application of MR damper in aero engine.