Takashi Chuda and Osamu Sano
Department of Physics, Faculty of General Education, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183, Japan
(Received February 26, 1994; Accepted April 11, 1994)
Keywords: Ferrofluid, Labyrinthian Structure, Numerical Simulation, Minimum Potential, Horton's Law
Abstract. An instability criterion of an initially flat interface of magnetic and nonmagnetic fluids confined in a Hele-Shaw cell, to which a uniform magnetic field is applied perpendicularly, is given analytically. Numerical simulation is made to investigate onset and further development of a perturbed interface. In the latter case, the direction of growth of the finger is determined each time by choosing the local minimum of the magnetic potential energy. Statistical properties of the resulting labyrinthian structure are similar to those observed in experiments.