On fundamentals of Rayleigh-Taylor turbulent mixing

We analyze symmetries, invariants, scaling and spectra of turbulent mixing induced by the Rayleigh-Taylor instability. The properties of this unsteady, anisotropic, and inhomogeneous turbulent process are found to depart from canonical Kolmogorov scenario. Time-and scale-invariance of the rate of momentum loss leads to non-dissipative momentum transfer between the scales, to 1/2 and 3/2 power-law scale dependencies of the velocity and Reynolds number respectively, and to spectra distinct from Kolmogorov. Turbulent mixing exhibits more order compared to isotropic turbulence, and its viscous and dissipation scales are set by the flow acceleration. Copyright (c) EPLA, 2010