Late Stage of Rayleigh-Taylor Instability

When a nearly flat fluid surface is subject to a small sinusoidal disturbance and a gravity or other acceleration field acts on the fluid so as to destabilize the surface, the irregularities grow exponentially with time in the regime of small amplitudes where linear theory applies Rayleigh. At larger amplitudes linear theory ceases to apply and the gas or magnetic field at the interface penetrates linearly with time into the fluid in the form of fingers or bubbles G.I. Taylor. The subsequent stage of successive mergers between fingers to make larger and faster ones is considered. To the extent that a statistical analysis is valid it is suggested that a free slab of fluid cannot be accelerated to more than about 50 times its won thickness without suffering breakthrough.