Long-range correlations and percolation regimes in the system with drift flows

Correlation effects play an important role in the description of turbulent transport. The present paper considers the influence of drift flow and time-dependence effects on the passive scalar behavior in the framework of the percolation approach. The renormalization method of a small parameter in continuum percolation models is reviewed. The modification is suggested of the renormalization condition of the small parameter of the percolation model in accordance with the additional external influences superimposed on the system. This approach makes it possible to consider simultaneously both parameters: the characteristic drift velocity U_d and the characteristic perturbation frequency omega . The effective diffusion coefficient D_eff {~} omega (1/7) satisfactorily describes the low-frequency region omega , where the long-range correlation effects play a significant role. The character of the dependence of D_eff on the drift flow amplitude U_d in different regimes is analyzed.