TY - JOUR
AU1 - Nurge, Mark A.
AU2 - Youngquist, Robert C.
AU3 - Starr, Stanley O.
AB - Modeling the interaction between a non-uniform magnetic field and a rotating conductive object provides insight into the drag force, which is used in applications such as eddy current braking and linear induction motors, as well as the transition to a repulsive force, which is the basis for magnetic levitation systems. Here, we study the interaction between a non-uniform field generated by a cylindrical magnet and a rotating conductive sphere. Each eddy current in the sphere generates a magnetic field which in turn generates another eddy current, eventually feeding back on itself. A two-step mathematical process is developed to find a closed-form solution in terms of only three eddy currents. However, the complete solution requires decomposition of the magnetic field into a summation of spherical harmonics, making it more suitable for a graduate-level electromagnetism lecture or lab. Finally, the forces associated with these currents are calculated and then verified experimentally.
TI - Drag and lift forces between a rotating conductive sphere and a cylindrical magnet
JF - The American Journal of Physics
DO - 10.1119/1.5024220
DA - 2018-06-06
UR - https://www.deepdyve.com/lp/american-association-of-physics-teachers/drag-and-lift-forces-between-a-rotating-conductive-sphere-and-a-4MYvdHyR1H
SP - 443
EP - 452
VL - 86
IS - 6
DP - DeepDyve