title: Pore-scale simulation of fluid flow and solute dispersion in three-dimensional porous media.
abstract: In the present work fluid flow and solute transport through porous media are described by solving the governing equations at the pore scale with finite-volume discretization. Instead of solving the simplified Stokes equation (very often employed in this context) the full Navier-Stokes equation is used here. The realistic three-dimensional porous medium is created in this work by packing together, with standard ballistic physics, irregular and polydisperse objects. Emphasis is placed on numerical issues related to mesh generation and spatial discretization, which play an important role in determining the final accuracy of the finite-volume scheme and are often overlooked. The simulations performed are then analyzed in terms of velocity distributions and dispersion rates in a wider range of operating conditions, when compared with other works carried out by solving the Stokes equation. Results show that dispersion within the analyzed porous medium is adequately described by classical power laws obtained by analytic homogenization. Eventually the validity of Fickian diffusion to treat dispersion in porous media is also assessed.
authors.affiliation: Division of Computer, Electrical and Mathematical Science and Engineering, King Abdullah University of Science and Technology, 23955-6900, Thuwal, Saudi Arabia and Institute for Computational Engineering and Sciences, University of Texas at Austin, 78712-0027, Austin, Texas, USA.
authors.forename: Matteo
authors.initials: M
authors.lastname: Icardi
authors.affiliation: Department of Applied Science and Technology, Politecnico di Torino, 10129 Torino, Italy.
authors.forename: Gianluca
authors.initials: G
authors.lastname: Boccardo
authors.affiliation: Department of Applied Science and Technology, Politecnico di Torino, 10129 Torino, Italy.
authors.forename: Daniele L
authors.initials: DL
authors.lastname: Marchisio
authors.affiliation: Department of Environment, Land and Infrastructures, Politecnico di Torino, 10129 Torino, Italy.
authors.forename: Tiziana
authors.initials: T
authors.lastname: Tosco
authors.affiliation: Department of Environment, Land and Infrastructures, Politecnico di Torino, 10129 Torino, Italy.
authors.forename: Rajandrea
authors.initials: R
authors.lastname: Sethi
mesh_terms: D057446:Hydrodynamics; D008958:Models, Molecular; D008968:Molecular Conformation; D016062:Porosity