Study on the vibration control method of a turboshaft engine rotor based on piezoelectric squeeze film damper oil film clearance

Abstract

In the complex environment of the battlefield and dust weather, hard objects including birds, bullets, sand and others will inevitably cause impact damage to the compressor blades of turboshaft engines. The damage will further result in fatigue vibration of the gas generator rotor and catastrophic accidents such as excessive engine vibration and even crash. The relation between oil film clearance of dampers and damping of rotor systems as well as the damping and vibration amplitude of a rotor system are analyzed. The functional relation between oil film clearance and vibration amplitude is derived. Taking the gas generator rotor of a certain turboshaft engine as an example, the rotor dynamic model of a gas generator rotor with oil film bearing clearance is constructed, and the vibration response of the rotor system under different oil film clearances is analyzed. A new type of squeeze film damper (SFD) structure with piezoelectric-driven split pads is innovatively designed, and the vibration control system of the gas generator rotor is built. In addition, experimental research on rotor fault vibration control under different oil film clearances is carried out. The results show that, within a certain range, when oil film clearance decreases, amplitude will decrease. Under the experimental conditions, when the driving voltage of the piezoelectric actuator is adjusted from 0 to 70 V, the oil film clearance decreases from 156 to 118 µm. Then, the vibration amplitude decreases and gradually reaches stability after 0.036 s, and the vibration amplitude of the rotor system decreases by 12 %. When the driving voltage of the piezoelectric actuator is adjusted to 150 V, the oil film clearance decreases to 76 µm, and the vibration amplitude of the rotor system decreases by 28 %. When the new SFD adopts a piezoelectric-driven split-pad structure, the structure can adjust quickly the oil film clearance online so as to control the vibration of the rotor system. The research results can provide a technical reference for the vibration control of turboshaft engine rotor systems.