The author presents a review of some experimental works devoted to the research of evolution of large-scale perturbations and turbulent mixing (TM) in liquid and gaseous media during the growth of hydrodynamic instabilities. In particular, it is shown that growth of perturbations and TM in gases is sensitive to the Mach number of shock wave; character of gas front penetration into liquid is not changed as the Reynolds number of flow increases from 5×10 5 to 10 7 ; and change of the Atwood number sign from positive to negative causes stopping of gas front penetration into liquid, but mixing zone width is expanded under inertia.

The results of the experimental study of the Reynolds number effect on the process of the Rayleigh-Taylor (R-T) instability transition into the turbulent stage are presented. The experimental liquid layer was accelerated by compressed gas. Solid particles were scattered on the layer free surface to specify the initial perturbations in some experiments. The process was recorded with the use of a high-speed motion picture camera. The following results were obtained in experiments: (1) Long-wave perturbation is developed at the interface at the Reynolds numbers Re < 10 4 . If such perturbation growth is limited by a hard wall, the jet directed in gas is developed. If there is no such limitation, this perturbation is resolved into the short-wave ones with time, and their growth results in gasliquid mixing. (2) Short-wave perturbations specified at the interface significantly reduce the Reynolds number Re for instability to pass into the turbulent mixing stage.

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