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| Titel |
Disorder versus correlation controlled non-Fickian transport in heterogeneous porous media: a correlated continuous time random walk approach |
| VerfasserIn |
Marco Dentz, Tanguy Le Borgne, Peter Kang, Diogo Bolster |
| Konferenz |
EGU General Assembly 2014
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250099398
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| Publikation (Nr.) |
 EGU/EGU2014-15172.pdf |
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| Zusammenfassung |
| Medium and flow heterogeneities lead to global transport patterns such as early and late
solute and particle arrivals, and non-linear dispersion which cannot be captured by
large scale models based on Fickian transport mechanisms. Such behaviors can be
modeled by non-Fickian approaches that are based on time and/or space non-local
conservation equations. A key question concerns the identification and quantification of the
heterogeneity controls on global non-Fickian transport patterns. Anomalous transport can be
viewed as a collective phenomenon generated by the complex interaction of small
scale fluctuations and mass transfer processes. Here, we focus on the roles of broad
heterogeneity distribution, and heterogeneity and flow correlation on global non-Fickian
transport. We identify the signatures of disorder and correlation dominated large scale
transport in the distributions of solute arrival times, solute dispersion and spatial solute
distributions. Starting from well-defined small scale stochastic flow and transport
descriptions, we quantify large scale transport by ensemble averaging over the Lagrangian
particle dynamics, which leads to a global transport model that is given by a coupled
continuous time random walk (CTRW) characterized by correlated particle velocities. We
formalize this correlated CTRW in terms of an evolution equation for the global
particle distribution, and discuss the impact of the correlation of subsequent particle
velocities on the transport behavior, as well as the limits of perfect and no correlation. |
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