Numerical and Experimental Investigation of the Development of Two-Dimensional Disturbances in the Case of Rayleigh–Taylor Instability and Transition to Turbulence

The results of experimental and numerical investigations of the development of two-dimensional determininistic disturbances in the case of Rayleigh–Taylor instability and transition to turbulence on the gas-liquid interface are presented. The experiments were performed on a light-gas gun. Disturbances at the interface were produced by means of gun oscillations using a special device. The disturbance wavelength varied from 5.4 to 8.8 mm, their amplitude from 0.3 to 0.4 mm, and the liquid layer acceleration from 5.2 to 18.8 mm/ms2. Water was used as a fluid and compressed air as a gas. The experimental data on the disturbance transition to the turbulent stage are obtained. The experiments are accompanied by the numerical modeling using the EGAK code. The criteria of instability transition to the turbulent stage are proposed.