Thermal–Elastic–Magnetic Coupling-Induced Rubbing Behaviors of a Bladed Thin-Walled Rotor with Distributed Magnetic Actuators

Abstract

A bladed thin-walled rotor with magnetic bearings in gas turbines has minimal wear to improve the service life. Especially, the rotor system can actively suppress vibrations. Yet, thermal–elastic–magnetic coupling-induced rubbing features of a bladed thin-walled rotor with magnetic bearings are not clear, and blade rubbing behaviors induced by high temperatures always occur in this kind of rotor. This paper establishes a new bladed thin-walled rotor model with distributed electromagnetic actuators to reduce thermoelastic vibrations and develops a solution approach for obtaining the thermal–elastic–magnetic coupling-induced rubbing characteristics of the rotor. The solution approach is verified, and the effectiveness of the distributed electromagnetic actuator model is demonstrated. The magnetic supports require two differential-control actuators at each position to generate the electromagnetic force, due to irregular concave–convex deformations of the rotor. Thereafter blade rub behaviors for the thin-walled rotor system are revealed. Uniform and smaller thermal deformations of the rotor system with the present actuator model avoid tip rub due to preventing thermal energy concentration. With the proper bearing capacity of a single actuator, an adequate number of actuators are required to ensure stability. The proposed theoretical prototype of the bladed thin-walled rotor with distributed electromagnetic actuators prevents blade rubbing caused by high temperatures. The provided solution approach can evaluate the vibration characteristics of a rotating thin-walled rotor with magnetic supports in the high-temperature environment.