An assessment of first-order stochastic dispersion theories in porous media

Research output: Contribution to journalArticle

29 Citations (Scopus)

Abstract

Random realizations of three-dimensional exponentially correlated hydraulic conductivity fields are used in a finite-difference numerical flow model to calculate the mean and covariance of the corresponding Lagrangian-velocity fields. The dispersivity of the porous medium is then determined from the Lagrangian-velocity statistics using the Taylor definition. This estimation procedure is exact, except for numerical errors, and the results are used to assess the accuracy of various first-order dispersion theories in both isotropic and anisotropic porous media. The results show that the Dagan theory is by far the most robust in both isotropic and anisotropic media, producing accurate values of the principal dispersivity components for σγ as high as 1.0. In the case of anisotropic media where the flow is at an angle to the principal axis of hydraulic conductivity, it is shown that the dispersivity tensor is rotated away from the flow direction in the non-Fickian phase, but eventually coincides with the flow direction in the Fickian phase.

Original languageEnglish
Pages (from-to)53-73
Number of pages21
JournalJournal of Hydrology
Volume199
Issue number1-2
DOIs
StatePublished - Dec 1 1997

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porous media
dispersivity
porous medium
anisotropic medium
hydraulic conductivity
statistics

ASJC Scopus subject areas

  • Soil Science
  • Earth-Surface Processes

Cite this

An assessment of first-order stochastic dispersion theories in porous media. / Chin, David A.

In: Journal of Hydrology, Vol. 199, No. 1-2, 01.12.1997, p. 53-73.

Research output: Contribution to journalArticle

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