Random-Walk Method to Simulate Pollutant Transport in Alluvial Aquifers or Fractured Rocks

Random walk simulation of miscible flow through heterogeneous 2D porous media considering dispersion tensor

“…In practice, we need a velocity map that conserves the local fluid mass balance for each grid cell and the local solute mass balance at any interface. Two approaches have been proposed in the literature to address this problem: a reflection principle (Ackerer, 1988;Cordes et al, 1991;Uffink, 1985) and an interpolation technique (LaBolle et al, 1996(LaBolle et al, , 1998. A brief review of these two approaches is presented here, and the reader is referred, in each case, to the original publications for more details.…”

Transport in a 2-D saturated porous medium: A new method for particle tracking

“…In classical particle methods, in order to take into account velocity variations between two adjacent meshes, one generally considers that the greatest distance covered during At should not exceed Ax/2 or ~x/3 (Ackerer, 1988;Uffink, 1988: Dzikowsky, 1992). …”

“…They simulate the physical processes of solute movement by following the progression of its particles. Although these methods are flexible (Goblet, 1981;Prickett, Naymick, and Lonnquist, 1981;Ackerer and Kinzelbach, 1985;Ackerer, 1988;Ackerer, Mose, and Semba, 1990;Uffink, 1990) and therefore can be adapted to many special situations, they are gluttons for computer time because they calculate the path line of each particle in the system. By combining the advantages of both preceeding methods, the management of particles proposed here is fast and flexible.…”

An object-oriented particle tracking code for pyrite oxidation and pollutant transport in mine spoil heaps

“…The basic concepts of the random walk method have been reviewed by several authors: Prickett et al (1981), Uffink (1985Uffink ( , 1988, Kinzelbach (1986Kinzelbach ( , 1988, Marsily (1986), Ackerer (1988), Valocchi & Quinodoz (1989), Tompson & Gelhar (1990), Kinzelbach & Uffink (1991), Kitanidis (1994), Zheng & Bennett (2002), LaBolle et al (1996), Wen & Kung (1996) and others. It can be demonstrated by a simple one-dimensional transport problem where the concentration distribution resulting from an instantaneous injection of mass, M, at location x ¼ 0 in an infinite column of porous medium in which there is uniform flow at a velocity, V, yields the concentration distribution at time t:…”