Nonclassical transport in highly heterogeneous and sharply contrasting media

We review the physical models of nonclassical transport processes in highly heterogeneous media with different types of the spatial distribution of characteristics. We discuss transport in regularly heterogeneous, fractal, and statistically homogeneous sharply contrasting media, as well as in liquid media under the condition of Rayleigh–Benard convection. The behavior of the impurity concentration in the main localization region and at asymptotically large distances from the source is analyzed. The effect on the transport regimes arising due to the presence of colloids, as well as barriers surrounding the impurity source, is investigated. An asymptotic approach to the calculation of the concentration in a medium with large-scale heterogeneities in the distribution of transport characteristics is presented.