Modeling a Ferrofluid in a Rotating Magnetic Field

B. A. Finlayson
Department of Chemical Engineering, University of Washington, Seattle, WA, USA

COMSOL Multiphysics is used to solve the problem of a ferrofluid placed in a rotating magnetic field, known as the spin-up problem. The spin-up phenomenon occurs when the fluid is contained in a cylinder and a homogeneous magnetic field rotates uniformly in the circular cross-section.

This work shows how to implement the pertinent equations in COMSOL Multiphysics and shows that the simulations agree with the experimental observations made over the past 40 years.

Simulations are also used to show that the proper boundary condition is zero spin on solid walls, because that is the only one that gives results in agreement with experiments.