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arXiv · 2101.05506

Pore-scale Mixing and the Evolution of Hydrodynamic Dispersion in Porous Media

Alexandre Puyguiraud·Philippe Gouze·Marco Dentz
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Abstract

We study the interplay of pore-scale mixing and network-scale advection through heterogeneous porous media, and its role for the evolution and asymptotic behavior of hydrodynamic dispersion. In a Lagrangian framework, we identify three fundamental mechanisms of pore-scale mixing that determine large scale particle motion, namely, the smoothing of intra-pore velocity contrasts, the increase of the tortuosity of particle paths, and the setting of a maximum time for particle transitions. Based on these mechanisms, we derive a theory that predicts anomalous and normal hydrodynamic dispersion based on the characteristic pore length, Eulerian velocity distribution and Péclet number.

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Alexandre Puyguiraud, Philippe Gouze, Marco Dentz. 2021-03-25. Pore-scale Mixing and the Evolution of Hydrodynamic Dispersion in Porous Media. https://doi.org/10.1103/physrevlett.126.164501

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