Motion stability of high-speed maglev systems in consideration of aerodynamic effects: a study of a single magnetic suspension system

摘要

In this study, the intrinsic mechanism of aerody-namic effects on the motion stability of a high-speed maglev system was investigated. The concept of a critical speed for maglev vehicles considering the aerodynamic effect is pro-posed. The study was carried out based on a single magnetic suspension system, which is convenient for proposing rele-vant concepts and obtaining explicit expressions. This study shows that the motion stability of the suspension system is closely related to the vehicle speed when aerodynamic effects areconsidered.Withincreasesofthevehiclespeed,thestabil-itybehavior of thesystemchanges. At acertainvehiclespeed, the stability of the system reaches a critical state, followed by instability. The speed corresponding to the critical state is the critical speed. Analysis reveals that when the system reaches the critical state, it takes two forms, with two criti-cal speeds, and thus two expressions for the critical speed are obtained. The conditions of the existence of the critical speed were determined, and the effects of the control parameters and the lift coefficient on the critical speed were analyzed by numerical analysis. The results show that the first crit-ical speed appears when the aerodynamic force is upward, and the second critical speed appears when the aerodynamic force is downward. Moreover, both critical speeds decrease with the increase of the lift coefficient.