ISSN:
1436-3259
Schlagwort(e):
Solute transport
;
random velocity
;
Lagrangian description
;
travel time
;
nonlinear effects
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Architektur, Bauingenieurwesen, Vermessung
,
Energietechnik
,
Geographie
,
Geologie und Paläontologie
Notizen:
Abstract The problem of one-dimensional transport of passive solute by a random steady velocity field is investigated. This problem is representative of solute movement in porous media, for example, in vertical flow through a horizontally stratified formation of variable porosity with a constant flux at the soil surface. Relating moments of particle travel time and displacement, exact expressions for the advection and dispersion coefficients in the Focker-Planck equation are compared with the perturbation results for large distances. The first- and second-order approximations for the dispersion coefficient are robust for a lognormal velocity field. The mean Lagrangian velocity is the harmonic mean of the Eulerian velocity for large distances. This is an artifact of one-dimensional flow where the continuity equation provides for a divergence free fluid flux, rather than a divergence free fluid velocity.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1007/BF01544177
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