A simple experiment to investigate two‐dimensional mixing by Rayleigh–Taylor instability

A simple experiment to study the mixing of two different density fluids by the Rayleigh–Taylor instability has been performed. Several experiments are reported for nominally one‐dimensional homogeneous mixing and for experiments characterized by a large two‐dimensional motion superimposed on the mixing process. The one‐dimensional experiments show a plane mixing region that expands by Rayleigh–Taylor instabilities. The two‐dimensional experiments show a contraction in the width of the mixing interface that is a result of the stretching action of the large‐scale motion. Image analysis techniques have been developed to provide quantitative measurements for use in a ‘‘two‐fluid’’ model of the mixing phenomena.