Abstract: The magnetic levitation force exerted on the magnets immersed in
ferrofluid is the theoretical basis of various application of ferrofluid. In
this paper, based on the equivalent magnetic charge models and the equivalent
current models of cylindrical magnets, magnetic charge image method and current
image method are used to calculate the magnetic levitation force exerted on the
cylindrical magnets immersed in ferrofluid respectively. The magnetic
levitation force under the same conditions is calculated by the Comsol
Multiphysics software according to the mechanical formula after the
distribution of the magnetic field is obtained using finite element method. The
magnetic levitation force is also measured experimentally, whose results are
compared with the theoretical results obtained by the three methods. The
analysis shows that the variation law of the magnetic levitation force and the
influence by various parameters can be evaluated by the calculation with
magnetic charge image method and current image method, but there is great
difference between the theoretical results and the experimental results, and
the greatest difference are 46% and 62% respectively. The agreement
between the theoretical and the experimental results is quite good when the
finite element method is used, whose greatest difference is 9%.
Keywords: Ferrofluid, magnets, magnetic levitation force, image method, finite element method
