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| Titel |
Lagrangian Transport Upscaling in Heterogeneous Media |
| VerfasserIn |
M. Dentz, T. Le Borgne, J. Carrera |
| Konferenz |
EGU General Assembly 2009
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 11 (2009) |
| Datensatznummer |
250022607
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| Zusammenfassung |
| Effective transport in heterogeneous environments is essentially different from transport in
homogeneous media. Spatial medium heterogeneities lead to non-Fickian features such as
breakthrough curve tailing and anomalous dispersion. Coarse graining of the microscale
transport equations implies the contraction of information. The latter leads to non-Markovian
behavior, which can be viewed as the cause of non-Fickian transport features. Using a
Lagrangian modeling framework, we discuss transport upscaling and uncertainty in
effective Lagrangian and Eulerian models for three different heterogeneity classes: (i)
microscale model for media characterized by weakly correlated disorder, (ii) mesoscale
model for media characterized by a correlated lognormally distributed hydraulic
conductivity and (iii) macroscale model for media characterized by strong Lagrangian
velocity correlations. The non-Markovianity of effective transport manifests itself in
different ways. In the first case, effective dynamics are described by a continuous time
random walk. In the second case, we find a persistent continuous time random
walk. In the third case, effective dynamics are summarized by a correlated random
walk. |
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