title: Anomalous transport on regular fracture networks: Impact of conductivity heterogeneity and mixing at fracture intersections.
abstract: We investigate transport on regular fracture networks that are characterized by heterogeneity in hydraulic conductivity. We discuss the impact of conductivity heterogeneity and mixing within fracture intersections on particle spreading. We show the emergence of non-Fickian transport due to the interplay between the network conductivity heterogeneity and the degree of mixing at nodes. Specifically, lack of mixing at fracture intersections leads to subdiffusive scaling of transverse spreading but has negligible impact on longitudinal spreading. An increase in network conductivity heterogeneity enhances both longitudinal and transverse spreading and leads to non-Fickian transport in longitudinal direction. Based on the observed Lagrangian velocity statistics, we develop an effective stochastic model that incorporates the interplay between Lagrangian velocity correlation and velocity distribution. The model is parameterized with a few physical parameters and is able to capture the full particle transition dynamics.
authors.affiliation: Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA.|Korea Institute of Science and Technology, Seoul 136-791, Republic of Korea.
authors.forename: Peter K
authors.initials: PK
authors.lastname: Kang
authors.affiliation: Institute of Environmental Assessment and Water Research (IDAEA), Spanish National Research Council (CSIC), 08034 Barcelona, Spain.
authors.forename: Marco
authors.initials: M
authors.lastname: Dentz
authors.affiliation: Université de Rennes 1, CNRS, Geosciences Rennes, UMR 6118, Rennes, France.
authors.forename: Tanguy
authors.initials: T
authors.lastname: Le Borgne
authors.affiliation: Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA.
authors.forename: Ruben
authors.initials: R
authors.lastname: Juanes
mesh_terms: D003198:Computer Simulation; D008390:Markov Chains; D008962:Models, Theoretical; D009010:Monte Carlo Method; D009038:Motion; D012996:Solutions
chemical_list: D012996:Solutions