DYNAMIC RESPONSE AND SUPPRESSION METHOD OF HIGH-SPEED ROTORS UNDER THE ROTARY INERTIAL MOMENT

Current studies on rotor dynamic response mainly focus on the unbalance forces caused by mass eccentricity, while little attention is paid to the rotary inertial moments caused by the skew angle of the principal axis of inertia. Especially for the rotors operating at high rotational speeds, the influence of rotary inertial moments on rotor response could not be ignored. Therefore, it is necessary to study the influence of rotary inertial moments on the rotor response and provide corresponding response suppression methods. This paper established a dynamic model based on the key structural characteristics of aero-engine high-pressure rotors. The excitations from mass eccentricity and skew of the principal axis of inertia are both considered. Numerical analysis was performed, which shows that the dynamic response excited by the unbalance force remains at a low level after passing the critical speed, however, the response excited by the rotary inertial moment increases continuously with the rotational speed, because of the self-centering of the principal axis of inertia at the high speed. Experiments are conducted on a test rig, results show that the decrease of local angular stiffness around the disk could reduce the influence of rotary inertial moments, eventually suppressing the dynamic response at high rotational speed.