Vibration suppression and multi-objective optimization of an aeroengine rotor system: Theory and experiment

Aeroengine rotor vibration seriously threatens unit operating safety, and squeeze film dampers (SFDs) are core passive vibration reduction components. This study investigates the optimization of vibration amplitude in a squeeze film damper-rotor system under constant speed or acceleration conditions. Dynamic models of the squeeze film damper-rotor system, the Non-dominated Sorting Genetic Algorithm II (NSGA-II), and the Multi-Objective Particle Swarm Optimization (MOPSO) algorithm were established. The factors influencing the dynamic characteristics of the squeeze film damper and the dynamic response of the rotor system were analyzed. Both optimization algorithms were employed to perform multi-objective optimization calculations for the steady-state and transient responses of the system. The results indicate that reducing the oil film thickness, along with increasing the damper length and oil viscosity, enhances the suppression of the unbalanced response of the rotor system. Both the NSGA-II and MOPSO algorithms demonstrated significant effectiveness in optimizing the steady-state response at typical locations within the squeeze film damper-rotor system, with a certain degree of effectiveness observed for the transient response as well. Quantitative comparison of six steady-state and six transient working conditions reveals that NSGA-II achieves optimal or good comprehensive performance in above working conditions. In contrast, MOPSO only delivers good or poor optimization results across transient cases, exhibiting an overall weaker vibration suppression performance. The findings provide a theoretical foundation for further research of multi-objective optimization in the dynamic response of rotor systems.