Flow And Transport Processes In Fractured Porous Media

Abstract

Flow and transport conditions in fractured porous media usually show a heterogeneous behaviour. Dispersive processes in the porous matrix lead to a slow but persistent advance of the solute front while advective processes in the fractures may induce rapid solute transport Mass exchange between fracture and matrix is possible in both directions due to fracture-matrix interaction The influence of the above processes depends mainly on the geometry of the fractured system and on the degree of contrast between the material properties of the matrix and fractures. In this paper a numerical approach is presented describing saturated flo a?V transport processes in arbitrarily fractured porous media. A fracture gen^ M.» is introduced to translate measured field data into discrete fracture p * ' models. The mesh generator is able to describe the complex ^, rat ?,. u a fractured porous rock system and provides a pre-refincmeil al iy fractures. Different types of elements are combined as necessary in order to couple the discrete fractured system with the continuous matrix system of the rock. The standard Galerkin finite element method is used to discretizc the flow equation and a Flux-Corrected Transport algorithm is employed to solve the transport equation. Both discretization techniques account for the unstructured grid provided by the mesh generator. An artificial data set is used to test the techniques presented. Transactions on Ecology and the Environment vol 17, © 1998 WIT Press, www.witpress.com, ISSN 1743-3541