Drift of levitated/suspended body in High-Tc superconducting levitation systems under vibration -: Part II:: Drift velocity for gap varying with time

To study levitation drift further, i.e., the gap between a superconductor and a permanent magnet varying with time in high-T-c superconducting levitation systems, drift velocity is introduced. Based on the numerical simulations of the dynamic response of a levitated body, and according to the essential reasons for drift, the drift velocity is first divided into two regimes: V-ff [related to flux flow (FF)] and V-fc [related to flux creep (FC)]. The drift velocity is shown to be mainly dependent upon properties of superconductivity (such as the critical current density of superconductors), initial disturbances, and applied excitations (such as the amplitude and the frequency of external excitations). Furthermore, the corresponding influences of the drift velocities V-ff and V-fc have been investigated quantitatively in this paper.