Research on active control method of rotor blade synchronous vibration based on additional secondary excitation forces

Abstract

In this paper, a synchronous vibration control method was proposed to avoid the high-cycle fatigue fracture of aeroengine rotor blade. Firstly. The harmonic force, causing synchronous vibration, was derived by Fourier series expansion by the mean of simplifying the aerodynamic exciting forces into the periodic rectangular pulse wave forces. It was found that the synchronous vibration can be controlled by adjusting the primary excitation forces parameters. Based on this, the additional secondary excitation forces were introduced to control the synchronous vibration caused by primary excitation forces. Secondly, the influences of the number, position, direction, duration of additional secondary excitation forces and the phase difference between additional secondary excitation forces and primary excitation forces on the synchronous vibration control were obtained through theoretical analysis, which was simulated and verified by a single-degree-of-freedom model. Thirdly, a high-speed straight blade test bench was established, and the feasibility of the method in controlling synchronous vibration of rotor blade was proved by adding additional magnet excitation forces on the basis of fixed magnet excitation forces. Finally, the suppression strategy of synchronous vibration of rotor blade by introducing additional secondary excitation forces was given. It can provide theoretical and technical support for effectively controlling the synchronous vibration amplitude and avoiding the high-cycle fatigue fracture of rotor blade in engineering practice.