Dynamics of freely-suspended drops

Ferrofluid drops are freely suspended for long periods in air in a novel ex periment by using magnetic fields to create an attractive force opposing gr avity. The suspended drop is then forced to oscillate by perturbing the sup porting magnetic field. In addition to small-amplitude behaviour, the drive n drop exhibits high order nonlinear modes of oscillation, and can be drive n until it splits. A new simplified analytical expression for the general p otential for the drop motion is derived, and numerical simulations of the d rop behaviour are presented, showing close agreement with the experimental data.