Experiments on self-similar Rayleigh–Taylor instability-induced
mixing in gases in the Earth's gravity conducted on the OSA
facility at the Russian Federal Nuclear Center–VNIITF are
described. These experiments are distinguished from other experiments,
usually performed with immiscible liquids in a tank or with miscible
liquids initially separated by a solid barrier that is retracted, in
that a membrane (of ∼1 μm thickness) with liquid soap film
embedded in a thin wire array (with microconductors of diameter 20
μm and with a spacing of 4 mm) initially separates the fluids. An
electric current to initiate the fluid interpenetration and mixing
destroys the membrane. Experiments performed for three different Atwood
numbers are described: in SF6-Ar with A = 0.54, in SF6-He with
A = 0.94, and in Kr-Ar with A = 0.35. Various
parameters of the mixing were measured from Schlieren photographs. In
particular, the dimensionless rate of mixing front growth is α =
0.078.
Analytic theory of self-similar mode-locking with rapidly varying mean-zero dispersion