English

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

Fluid Dynamics 2021-04-28 v2 Soft Condensed Matter Geophysics

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 P\'eclet number.

Keywords

Cite

@article{arxiv.2101.05506,
  title  = {Pore-scale Mixing and the Evolution of Hydrodynamic Dispersion in Porous Media},
  author = {Alexandre Puyguiraud and Philippe Gouze and Marco Dentz},
  journal= {arXiv preprint arXiv:2101.05506},
  year   = {2021}
}