Magnetic Fluid Flows in a Rotating Magnetic Field (Shape of Free Surface and Circulation Velocity)

Abstract

The shape of the free surface and circulation velocity of a magnetic fluid induced by a rotating magnetic field were investigated. In the experiment, the shapes of the free surface were measured with an electrical contact probe, and the circulation velocity by the surface floating method. The deformation was increased with an increase in the strength of the applied current irrespective of the frequency. On the other hand, the induced flow velocity was almost proportional to that of the phase of the magnetic field. In the analyses, the shapes of the free surface were analyzed by a perturbation method neglecting the surface velocity and surface tension. The profiles of the rotational velocity were also calculated using Glazov's equation. The results agreed with the experimental ones and showed that the deformation was induced mainly by the radial gradient of the magnetic field and Maxwell's interfacial stress.