Heterogeneous Saturated Mass Transport

Project file on GitHub

Overview

This example involves the usage of a cell-based heterogeneous parameterization for the parameter “intrinsic permeability”. We show a 2D and a 3D setup and compared the results to those from OGS5; the original examples are described in chapter “5.2 Groundwater flow in a heterogeneous medium” in Kolditz et al. (2012).

We extended the setup to show mass transport in the heterogeneous medium for testing.

Problem description

The setups are steady-state for flow, with an extent of a \(100\) m x \(100\) m horizontal plane for the 2D setup and a \(100\) m x \(100\) m x \(50\) m cube for the 3D setup. Mesh elements have side lengths of \(1\) m. The initial conditions are hydrostatic and concentration \(c=0\). The boundary conditions are translated into equivalent hydrostatic pressure values from hydraulic heads \(h_{left}=10\) m and \(h_{right}=9\) m and for concentration \(c_{left}=1\), \(c_{right}=0\) for left and right sides, respectively. All other sides are defined as no-flow (Zero-Neumann).

Porosity is \(0.01\), specific storage is \(0\), fluid density is \(1000\) kg\(\cdot\)m\(^3\), dynamic viscosity is \(10^{-3}\) Pa\(\cdot\)s, molecular diffusion coefficient is \(2\cdot 10^{-9}\) m\(\cdot\)s\(^{-2}\), dispersivities are longitudinal \(1\) m and transverse \(0.1\) m. The heterogeneous parameter fields of intrinsic permeability are shown in the figures below; creation of the tensor field is documented here.

Magnitude of isotropic permeability tensor for 2D setup.

Magnitude of isotropic permeability tensor for 3D setup.

Model results

The comparison of velocity and hydraulic head are shown below. The numerical results of OGS6 fit very well to the OGS5 results with relative differences for velocity in the order of ca \(10^{-2}\) and for hydraulic head in \(10^{-4}\).

Relative differences of 2D simulation results between OGS5 and OGS6. On the top left figure, white lines represent hydraulic head values of OGS5, blue lines of OGS6.

Relative differences of 3D simulation results between OGS5 and OGS6. On the top left figure, grey dots represent hydraulic head values of OGS6.

The mass transport simulation results (figures below) show an expected heterogeneous mass front moving through the domain.

Concentration distribution at simulation time $1e8$ s for the 2D setup.

Concentration distribution at simulation time $1e8$ s for the 3D setup.

The project files for the 2D setup are here. The project files for the 3D setup are here.

Literature

Kolditz, O., Görke, U.-J., Shao, H., Wang, W., 2012. Thermo-Hydro-Mechanical-Chemical Processes in Porous Media: Benchmarks and Examples, Lecture notes in computational science and engineering. Springer. ISBN: 3642271766.


This article was written by Marc Walther. If you are missing something or you find an error please let us know. Generated with Hugo 0.47.1. Last revision: September 12, 2018
Commit: [web] Fix LaTeX formulae with escaped _. 0f264ec51  | Edit this page on

Creative Commons License | Privacy policy / Legal statements / Impressum