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Bibliographic Details
Main Authors: Hermansen, Joachim Marco, Durhuus, Frederik Laust, Bjørk, Rasmus
Format: Preprint
Published: 2025
Subjects:
Online Access:https://arxiv.org/abs/2502.04410
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author Hermansen, Joachim Marco
Durhuus, Frederik Laust
Bjørk, Rasmus
author_facet Hermansen, Joachim Marco
Durhuus, Frederik Laust
Bjørk, Rasmus
contents The Ucar effect is a simple yet astonishing phenomenon where a permanent magnet can be levitated by placing it in the vicinity of another permanent magnet that rotates sufficiently fast. The few previous works on this type of magnetic levitation all required magnets rotating on the order of 200 Hz. Here we investigate the influence of applying a static magnetic field on the rotation axis and show that this can lower the needed rotation frequency to below 50 Hz. We explain this by a detailed analysis of the force producing levitation, which is a superposition of a repelling force caused by the off-axis (rotating) magnetic field and an attractive force due to the on-axis field. We study this force and resulting levitation experimentally, analytically and numerically for three different rotor magnet configurations, showing that trends in the levitation distance and frequency range can be accurately predicted from both the numerical and analytical models.
format Preprint
id arxiv_https___arxiv_org_abs_2502_04410
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Magnetic levitation at low rotation frequencies using an on-axis magnetic field
Hermansen, Joachim Marco
Durhuus, Frederik Laust
Bjørk, Rasmus
Classical Physics
The Ucar effect is a simple yet astonishing phenomenon where a permanent magnet can be levitated by placing it in the vicinity of another permanent magnet that rotates sufficiently fast. The few previous works on this type of magnetic levitation all required magnets rotating on the order of 200 Hz. Here we investigate the influence of applying a static magnetic field on the rotation axis and show that this can lower the needed rotation frequency to below 50 Hz. We explain this by a detailed analysis of the force producing levitation, which is a superposition of a repelling force caused by the off-axis (rotating) magnetic field and an attractive force due to the on-axis field. We study this force and resulting levitation experimentally, analytically and numerically for three different rotor magnet configurations, showing that trends in the levitation distance and frequency range can be accurately predicted from both the numerical and analytical models.
title Magnetic levitation at low rotation frequencies using an on-axis magnetic field
topic Classical Physics
url https://arxiv.org/abs/2502.04410