Anomalous diffusion in generalized Dykhne model

Contaminant transport is investigated in the generalized Dykhne model differing from the original Dykhne model by the presence of advection in the high-permeability medium. An analysis is presented of transport regimes and concentration tail behavior in the high-permeability medium. It is found that the transport regimes include anomalous ones: subdiffusion and quasi-diffusion. A difference is revealed between longitudinal and transverse transport. Regime change over time leads to multiple-regime long-distance asymptotic behavior of concentration distributions. An analogy is drawn between the problems examined here and transport through comb structures.