Vertical and lateral forces, torque and potential energy as a magnetic dipole with arbitrary angle moves laterally above a flat high-temperature superconductor

• Published in: Cryogenics (Guildford) Vol. 124; p. 103465
• Main Authors: Yang, Yong, Yang, Shuaijie, Yang, Wenli, Wu, Yunyi
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Ltd 01-06-2022; Elsevier BV
• Subjects: Anisotropy; Critical current density; Frozen-image model; High temperature superconductors; High-temperature superconductor; Lateral movement; Magnetic dipole; Magnetic dipoles; Magnetic levitation; Magnetic levitation systems; Magnetism; Permanent magnets; Potential energy; Torque; Vertical and lateral forces; Vertical forces; Lateral movement; Torque; Frozen-image model; High-temperature superconductor; Magnetic dipole; Vertical and lateral forces
• ISSN: 0011-2275; 1879-2235
• DOI: 10.1016/j.cryogenics.2022.103465

•The vertical and lateral forces decrease as θ increases from 0 to π/2.•Both of the lateral and vertical forces change as positive or negative cosine laws.•The torque Ty changes as a positive sine law fashion.•Intersection point of Ty moves towards the upper left orientation with increasing θ.•Total potential energy significantly increases as θ increases from 0 to π/2.
In the magnetic levitation system consisted of permanent magnets (PMs) and high-temperature superconductors (HTSs), the magnetization direction of the PM is often inconsistent with the c-axis of the HTS. Therefore, the interaction between the PM with an angle and the HTS should be studied to obtain the effects of the angle on the levitation properties due to the anisotropy property of the critical current density. In this paper, as the PM dipole oriented with the angle with respect to the c-axis of the HTS moves laterally above the semi-infinite HTS, the exact expressions for the lateral and vertical forces, the torque, and the total potential energy are obtained by using the advanced frozen-image model. The dependence of these physical quantities upon the angle and the initial cooling height have been systematically studied. Under the same conditions, the predicted force and torque calculations provided by the advanced frozen-image model qualitatively agree with the previous experimental and theoretical results. The study can provide some theoretical references for designing the HTS levitation system with the angle.