3D numerical simulation of Rayleigh-Taylor instability using MAH-3 code

A 3D numerical study of the turbulent phase of the evolution of Rayleigh-Ta ylor instability (RTI) was undertaken using the MAH-3 code. A criterion and a technique have been developed that can be used for diagnostics in comput ational experiments studying flow transition to self-similar turbulence. It has been found that a criterion of the flow transition to the self-similar turbulence is Kolmogorov's self-similar distribution of the turbulent kine tic energy together with the square law of mixing zone extension. The techn ique is based on the analysis of the evolution of the dimensionless power s pectrum of specific kinetic energy. Three phases of nonlinear mixing are fo und: "relict chaos", "formation of classical energy spectrum" and "spectrum degradation." Determination of a proportionality factor for a square law w ithin the time range incorporating inertial interval gives the value of alp ha approximate to 0.07.