Determination of particle transfer in random walk particle methods for fractured porous media

Abstract

A commonly used numerical scheme to simulate solute transport in the subsurface is the random walk particle method (RWPM). While significant progress has been made in developing random walk particle algorithms for porous media, an RWPM for fractured porous media, represented by dual continua, has not yet been developed in the literature. A key issue in developing an RWPM for fractured porous media is the determination of particle transfer between the two continua. In this study a relatively simple, yet physically based scheme to determine the particle transfer is developed. The usefulness of the scheme is demonstrated by comparing solute transport results determined from the proposed scheme with (1) an analytical solution for solute transport in a fractured porous medium with parallel fractures and (2) a numerical simulation obtained using the TOUGH2 code, a simulator for multiphase and multicomponent flow and transport in fractured porous media.