EFFECT OF LONG-RANGE CORRELATIONS ON TRANSPORT PHENOMENA IN DISORDERED MEDIA

Three different flow and transport phenomena considered here are hydro dynamic dispersion in heterogeneous porous media and aquifers, transpo rt of passive particles in an oscillating flow field, and miscible dis placement processes in heterogeneous reservoirs. At microscales all th ree phenomena are described by the classical convective-diffusion equa tion (CDE). The presence of long-range correlations at macroscales giv es rise to a rich variety of phenomena that cannot be predicted by ana lyzing the CDE by classical methods. In particular, a new percolation model with long-range correlations provides a rational explanation for the hitherto unexplained field-scale experimental data for hydrodynam ic dispersion in porous media and aquifers. Moreover, for transport in oscillating flow in convection cells percolation provides a novel rel ation between the dispersion coefficient and the Peclet number that ca nnot be predicted by other methods.