Random walk particle tracking simulations of non-Fickian transport in heterogeneous media

Journal Article · Tue Jun 01 04:00:00 EDT 2010 · Journal of Computational Physics

DOI:https://doi.org/10.1016/j.jcp.2010.02.014· OSTI ID:21333909

Viswanathan, H ^[1]; Berkowitz, B ^[2]; Robinson, B A ^[1]

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1. Earth and Environmental Sciences Division, Los Alamos National Laboratory, Los Alamos, New Mexico (United States)
2. Department of Environmental Sciences and Energy Research, Weizmann Institute of Science, Rehovot (Israel)

Derivations of continuum nonlocal models of non-Fickian (anomalous) transport require assumptions that might limit their applicability. We present a particle-based algorithm, which obviates the need for many of these assumptions by allowing stochastic processes that represent spatial and temporal random increments to be correlated in space and time, be stationary or non-stationary, and to have arbitrary distributions. The approach treats a particle trajectory as a subordinated stochastic process that is described by a set of Langevin equations, which represent a continuous time random walk (CTRW). Convolution-based particle tracking (CBPT) is used to increase the computational efficiency and accuracy of these particle-based simulations. The combined CTRW-CBPT approach enables one to convert any particle tracking legacy code into a simulator capable of handling non-Fickian transport.

• OSTI ID: 21333909
• Journal Information: Journal of Computational Physics, Journal Name: Journal of Computational Physics Journal Issue: 11 Vol. 229; ISSN JCTPAH; ISSN 0021-9991
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ALGORITHMS
GRAPH THEORY
LANGEVIN EQUATION
PARTICLES
RANDOMNESS
SIMULATION
SIMULATORS
STOCHASTIC PROCESSES
TRANSPORT THEORY