Interfacial instability of magnetic fluids in a rectangular container.

Abstract

An experimental and theoretical study is presented for the interfacial instability of magnetic fluids in rectangular containers subject to magnetic fields. Experiments were performed to determine the critical field intensity for incipient instability and to observe the growth of instability waves. Magnetic fluids used in the experiments were water-base ferricolloid W-35 and its dilution with distilled water. It was found that interfacial instability appeared when the field intensity exceeded the threshold value and grew in amplitude with the field intensity. It was also found that the wave number for the instability depended upon the field intensity and the dimensions of the container. The possible equilibrium configuration was analyze theoretically by minimizing the total energy. The experimental results can be explained well by the theoretical analysis.