Premium
Miscible Displacement: An Interacting Flow Region Model
Author(s) -
Skopp J.,
Gardner W. R.
Publication year - 1992
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj1992.03615995005600060004x
Subject(s) - dispersion (optics) , porous medium , displacement (psychology) , moment (physics) , mechanics , flow velocity , flow (mathematics) , velocity moments , equivalence (formal languages) , taylor dispersion , physics , materials science , thermodynamics , mathematics , porosity , classical mechanics , diffusion , optics , psychology , wavefront , discrete mathematics , zernike polynomials , composite material , psychotherapist
No existing microscopically based models of solute transport in porous media are completely satisfactory. In particular, it is difficult to a priori provide an estimate of the hydrodynamic dispersion coefficient. We developed a model of solute movement in saturated porous materials that starts with a continuous velocity distribution instead of an average velocity. The model allows transfer of solute between regions of differing velocity. This transfer is characterized by an interaction coefficient. An approximate solution for large interaction is obtained using the method of moments. This technique shows the equivalence of the model moments to those of the classical dispersion equation. The second moment yields the dependence of the dispersion coefficient on average velocity. The empirical dependence of dispersion on average velocity is recovered if the interaction is assumed to be a linear function of the average velocity. The model also predicts the increase in dispersion observed for heterogenous materials over that for a similar homogeneous material.