The mixing of contacting substances is considered. The evolution of the mix
ing layer over a long time period from multimode initial perturbations is i
nvestigated numerically in the short-scale and wide-range cases. In the cas
e of a short-scale initiation, the flow is stochastic in the sense that the
time of the considered evolution exceeds the period of correlation. The ef
fect of the amplitude of wide-range perturbations on the dynamics of mixing
is analyzed. The scale-invariant properties of the spectral and statistica
l parameters of turbulent mixing are investigated for the first time. The u
niversal spectra characterizing the turbulence mixing in the entire self-si
milar interval on a unified basis are obtained. The simulation is based on
the effective algorithms with high approximating qualities, which have been
tested earlier. (C) 2001 MAIK "Nauka/ Interperiodica".