Abstract
A unique numerical calculation method was constructed in order to analyze the static and dynamic characteristics of the diamagnetic bearing. An experimental setup consisting of a permanent magnet rotor, levitated with the arrangement of ferrite magnet and bismuth blocks, was used to confirm theoretical calculations. The stability analysis of the bearing relating to the vertical and lateral forces was incorporated with the dynamic model. The interaction force between the rotor magnet and the diamagnetic materials was modeled with the Amperian current approach via the diamagnetic-mirror-image concept. The magnetic potential of the system, which provides the equation of motion, was stated in terms of diamagnetic and gravitational interactions. The equations of motion of the dynamic part of the system were stated as a function of lateral, vertical, and tilt angles. Correlation of the vibrations such as vertical, radial, and tilt was determined with a numerical calculation obtained by the Runge-Kutta method. Translational and rotational tests together with the theoretical calculations showed the equilibrium position of the rotor to be stable statically and dynamically. The permanent magnet was spun up under vacuum conditions and then let to free spin down to analyze its dynamics.
| Original language | English |
|---|---|
| Article number | 034510 |
| Journal | Journal of Applied Physics |
| Volume | 103 |
| Issue number | 3 |
| DOIs | |
| Publication status | Published - 2008 |
| Externally published | Yes |
Funding
This work was partially supported by the Ataturk University Research Grant No. 167 and the U.S. Department of Energy. FIG. 1. Schematic view of a permanent magnet levitated with diamagnetic design. FIG. 2. Rotational decay rate of the permanent magnet as a function of frequency. FIG. 3. Vertical force vs distance between the levitated magnet and lifter magnet for Amperian and dipole approaches. FIG. 4. Vertical restoring force as a function of vertical displacement for various radial displacements. FIG. 5. Estimation of resonance frequencies from FFT in vertical, radial, and tilt directions.
| Funders | Funder number |
|---|---|
| Ataturk University | 167 |
| U.S. Department of Energy |