Tracer Dispersion in Porous Media with Spatial Correlations
  We analyze the transport properties of a neutral tracer in a carrier fluid flowing through percolation-like porous media with spatial correlations. We model convection in the mass transport process using the velocity field obtained by the numerical solution of the Navier-Stokes and continuity equations in the pore space. We show that the resulting statistical properties of the tracer can be approximated by a Levy walk model, which is a consequence of the broad distribution of velocities plus the existence of spatial correlations in the porous medium. 
Hernan A. Makse (UFC, Brazil), Jose S. Andrade Jr. (UFC, Brazil), and   H. Eugene Stanley (BU)