Global random walk solvers for fully coupled flow and transport in saturated/unsaturated porous media

Suciu N, Illiano D, Prechtel A, Radu AF (2021)

Publication Language: English

Publication Status: Accepted

Publication Type: Journal article, Original article

Future Publication Type: Journal article

Publication year: 2021

Journal

Advances in Water Resources Elsevier

Publisher: Elsevier

Book Volume: 152

Article Number: 103935

DOI: 10.1016/j.advwatres.2021.103935

Open Access Link: https://doi.org/10.1016/j.advwatres.2020.103558

Abstract

In this article, we present new random walk methods to solve flow and transport
problems in saturated/unsaturated porous media, including coupled flow and transport
processes in soils, heterogeneous systems modeled through random hydraulic
conductivity and recharge fields, processes at the field and regional scales. The
numerical schemes are based on global random walk algorithms (GRW) which
approximate the solution by moving large numbers of computational particles on
regular lattices according to specific random walk rules. To cope with the nonlinearity
and the degeneracy of the Richards equation and of the coupled system, we
implemented the GRW algorithms by employing linearization techniques similar to the
L-scheme developed in finite element/volume approaches. The resulting GRW Lschemes
converge with the number of iterations and provide numerical solutions that
are first-order accurate in time and second-order in space. A remarkable property of
the flow and transport GRW solutions is that they are practically free of numerical
diffusion. The GRW solvers are validated by comparisons with mixed finite element
and finite volume solvers in one- and two-dimensional benchmark problems. They
include Richards' equation fully coupled with the advection-diffusion-reaction equation
and capture the transition from unsaturated to saturated flow regimes.

Authors with CRIS profile

Nicolae Suciu Lehrstuhl für Angewandte Mathematik (Modellierung und Numerik) Alexander Prechtel Lehrstuhl für Angewandte Mathematik (Modellierung und Numerik)

Involved external institutions

University of Bergen / Universitetet i Bergen NO Norway (NO)

How to cite

APA:

Suciu, N., Illiano, D., Prechtel, A., & Radu, A.F. (2021). Global random walk solvers for fully coupled flow and transport in saturated/unsaturated porous media. Advances in Water Resources, 152. https://dx.doi.org/10.1016/j.advwatres.2021.103935

MLA:

Suciu, Nicolae, et al. "Global random walk solvers for fully coupled flow and transport in saturated/unsaturated porous media." Advances in Water Resources 152 (2021).

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