Author(s)

A. Aigueperse & M. Quintard

Abstract

Active dispersion occurs in aquifers when the flowing water exchanges matter with a trapped liquid phase. Two types of macroscopic models can be built depending whether the assumption of local chemical equilibrium is valid or not. A non local equilibrium model has been derived by the method of volume averaging. This method provides several closure problems which can be used to determine the effective transport coefficients from the pore-scale geometry. Numerical models are presented for two-dimensional unit cells representative of the pore structure and the trapped liquid phase geometry. Active dispersion tensors, mass exchange coefficients, and some additional modified convective terms that appear in the macroscopic equation were calculated. Correlations versus the Pec

Keywords