Production of reproducible Rayleigh–Taylor instabilities

A device is described that excites individual modes of the standing wave spectrum for surface waves on water in a water tank of rectangular cross section. By synchronizing the downward acceleration of the tank with the standing wave on the water, Rayleigh-Taylor instabilities with reproducible characteristics are excited at the air-water interface. By controlling the width of the tank, the fluid motion is made to be largely two dimensional. The reproducibility of the phenomenon and the two-dimensional character of the flow make it possible, for the first time, to compare details of the wave profile with results predicted with the two-dimensional models of Emmons, Chang, and Watson.