Flow Intermittency, Dispersion, and Correlated Continuous Time Random Walks in Porous Media

Pietro de Anna (1) , Tanguy Le Borgne (1) , Marco Dentz (2) , Alexandre M. Tartakovsky (3) , Diogo Bolster (4) , Philippe Davy (1)

1 GR - Géosciences Rennes
2 IDAEA - Institute of Environmental Assessment and Water Research
3 PNNL - Pacific Northwest National Laboratory
4 CEEES - Department of Civil and Environmental Engineering and Earth Science [Notre Dame]

We study the intermittency of fluid velocities in porous media and its relation to anomalous dispersion. Lagrangian velocities measured at equidistant points along streamlines are shown to form a spatial Markov process. As a consequence of this remarkable property, the dispersion of fluid particles can be described by a continuous time random walk with correlated temporal increments. This new dynamical picture of intermittency provides a direct link between the microscale flow, its intermittent properties, and non-Fickian dispersion.

Domains: Sciences of the Universe [physics]; Earth Sciences; Sciences of the Universe [physics]; Earth Sciences; Hydrology; Environmental Sciences; Global Changes

Pietro de Anna, Tanguy Le Borgne, Marco Dentz, Alexandre M. Tartakovsky, Diogo Bolster, et al.. Flow Intermittency, Dispersion, and Correlated Continuous Time Random Walks in Porous Media. Physical Review Letters, 2013, 110, pp.184502. ⟨10.1103/PhysRevLett.110.184502⟩. ⟨insu-00836057⟩