On the spectral and statistical properties of Rayleigh-Taylor mixing

Dynamics of turbulent mixing due to the Rayleigh-Taylor instability is cons idered. The mixing layer consists of a single horizontal array of large-sca le structures. The characteristics of these structures are studied by the s pectral and statistical methods. Mixing stimulation by long-wavelength nois e is studied. It is demonstrated that, for typical homogeneous unscaled noi se, self-similarity h proportional to t (2) is retained. The threshold ampl itude of random broadband noise is determined, below which this noise can b e ignored. The mixing deceleration by the side boundaries is studied. The s timulation and deceleration effects sizably influence the mixing coefficien t alpha (+), increasing and decreasing it, respectively. (C) 2000 MAIK "Nau ka/Interperiodica".