How a rotating magnetic field causes ferrofluid to rotate
M. I. Shliomis
Abstract
The spin-up effect - entrainment of a ferrofluid by a rotating magnetic field - is still poorly understood despite its 50-year history and many published works. This work shows that the generally accepted theory of spin diffusion can not explain this effect due to the completely insignificant value of the spin viscosity of real ferrofluids. Instead, it is shown that the heat generated in the micro-eddies that arise around the rotating magnetic particles makes the fluid magnetization inhomogeneous, and this is enough to explain the bulk flow in the fluid. The flow rate is proportional to the cubes of the field rotation frequency and the vessel radius.
Topics & Concepts
FerrofluidMagnetic fieldMagnetizationCondensed matter physicsMechanicsRotating magnetic fieldPhysicsRotation (mathematics)ViscosityMaterials scienceThermodynamicsGeometryMathematicsQuantum mechanicsCharacterization and Applications of Magnetic NanoparticlesGeomagnetism and Paleomagnetism StudiesSolar and Space Plasma Dynamics