Rayleigh-Taylor Instabilities by means of magnetic levitation of fluids

 The RT instability, in which a dense fluid invades a less dense fluid under acceleration such as gravity, is pervasive throughout nature.  General RT instabilities lie at the heart of myriad applications and diverse phenomena.  For example, RT instabilities occur during liquid impact and atomization, the explosion of supernovae, inertial confinement fusion, and in granular media.  More prosaically, the RT instability affects resolution control of ink-jet printers and appears when a bottle of vinegar-and-oil salad dressing is turned upside down.

    Experimental work on the RT instability in fluids has, until now, been plagued by jitter during acceleration of the tank that contains the fluids.  Here I will discuss our development of an alternate method that obviates this problem, viz., magnetic levitation of the dense fluid above the less dense fluid.  Using this approach, we have been able to obtain a dispersion relationship for the instability for not only a two fluid / one-interface system, but multiple layers as well.  In the latter case, the multiple interfaces are found to couple and modify the dispersion relationship when the intervening fluid layer is sufficiently thin.  I will compare our experimental results with long-standing, but until now never tested, theoretical predictions.