Difference between revisions of "Modeling tools"

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* Overview of modeling tools
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* Overview of modeling tools and software
 
* Useful little tools and helpers
 
* Useful little tools and helpers
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* Spreadsheet tool for flow field under pumped conditions
 
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The following list shows some selected modeling tools that can be used for the simulation of fracture flow and transport.
 
The following list shows some selected modeling tools that can be used for the simulation of fracture flow and transport.
Their capabilities with respect to modeling flow and transport in fractured media are compared in the chapter [[ Comparison of capabilities ]].
+
<!-- Their capabilities with respect to modeling flow and transport in fractured media are compared in the chapter [[ Comparison of capabilities ]] (will come soon). -->
  
 
=== COMSOL Multiphysics ===
 
=== COMSOL Multiphysics ===
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It is well suited for computing flow and transport in limestone aquifers.
 
It is well suited for computing flow and transport in limestone aquifers.
 
It provides predefined physics-based interfaces (e.g. a module for subsurface flow) and allows equation-based modeling, where arbitrary partial differential equations can be solved.
 
It provides predefined physics-based interfaces (e.g. a module for subsurface flow) and allows equation-based modeling, where arbitrary partial differential equations can be solved.
Different physics can be coupled, so a flow model can be coupled with a transport model.
+
Different physics can be coupled, e.g., a flow model can be coupled with a transport model.
The toolbox provides tools for geometry and mesh generation, a user interface for the simulation setup, several different solvers, and visualization and post-processing tools.
+
The toolbox provides tools for geometry and mesh generation, a user interface for the simulation setup, several direct and indirectsolvers, and visualization and post-processing tools.
 +
It uses the finite-element method and includes higher-order discretization schemes.
  
Discretization methods etc.
+
For the modeling of flow and transport in porous media, there are predefined physics interface available.
 +
Fractures can be included as additional discrete features.
  
For the modeling of flow in fractures, there is a predefined physics interface available.
+
Another option is to use the PDE interface of COMSOL.
However, there is no fracture transport interface yet, but it is possible to manually include the fracture transport physics.
+
The flow and transport equations are implemented as partial differential equations and the fracture flow and transport can be added using a feature called "Weak contributions".
The flow and transport equations can be implemented as partial differential equations and the fracture flow and transport can be added using a feature called "Weak contributions".
+
Here is an instruction file which describes how to setup a 2-dimensional flow and transport model including fracture flow and transport in COMSOL Multiphysics using the PDE interface.
Here is an instruction file which describes how to setup a 2-dimensional flow and transport model including fracture flow and transport in COMSOL Multiphysics.
+
* [[:File:WeakFormulation_toolbox.pdf |Instructions for setting up a discrete-fracture model in COMSOL Multiphysics (PDF) - DRAFT!]]
* [[:File:WeakFormulation_toolbox.pdf |Instructions for setting up a discrete-fracture model in COMSOL Multiphysics (PDF)]]
 
<!--
 
More details about the software can be found on the COMSOL webpage:
 
* [https://www.comsol.com Comsol Multiphysics]
 
-->
 
  
 
=== FEFlow ===
 
=== FEFlow ===
[http://www.mikepoweredbydhi.com/products/feflow FEFlow] is a simulator focused on groundwater flow and transport of contaminants, groundwater age and heat in porous media.
+
[http://www.mikepoweredbydhi.com/products/feflow FEFlow] is a finite-element simulator focused on groundwater flow and transport of contaminants, groundwater age and heat in porous media.
 
It comprises mesh generators, solvers and post-processing tools for visualization and result evaluation.
 
It comprises mesh generators, solvers and post-processing tools for visualization and result evaluation.
 
It facilitates the computation of porous medium flow and transport in 2D and 3D aquifers, which can be confined, semi-confined or unconfined.
 
It facilitates the computation of porous medium flow and transport in 2D and 3D aquifers, which can be confined, semi-confined or unconfined.
Unsaturated flow can also be modeled with an approach that uses the Richards model.
+
Unsaturated flow can also be modeled with based on the Richards model.
 
(Hydro-)geologic data can be easily imported and discrete fractures can be included.
 
(Hydro-)geologic data can be easily imported and discrete fractures can be included.
  
 
=== TOUGH ===
 
=== TOUGH ===
* [http://esd1.lbl.gov/research/projects/tough/ TOUGH]
+
* [https://tough.lbl.gov/ TOUGH]
  
 
=== DuMuX ===
 
=== DuMuX ===
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* [http://fracman.golder.com/ FRACMAN]
 
* [http://fracman.golder.com/ FRACMAN]
  
[[ Comparison of capabilities ]]
+
<!-- [[ Comparison of capabilities ]] - ''will come soon'' -->
  
 
== Useful helpers ==
 
== Useful helpers ==
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Some of them will be described in the following.
 
Some of them will be described in the following.
  
[[File:CaptureZones_Akacievej.png |thumb| Example of a capture zone calculation for a field site in Hedehusene. The blue lines are calculated streamlines and the green lines are simulated isopotentials.]]
+
[[File:CaptureZones_Akacievej.png |thumb| Example of capture zone calculations for the wells around the Akacievej site in Hedehusene. The blue lines are calculated streamlines and the green lines are simulated isopotentials.]]
  
 
=== Capture zone delineation of extraction wells (Matlab model) ===
 
=== Capture zone delineation of extraction wells (Matlab model) ===
Contaminated sites can often pose a threat to water suppliers.
+
Contaminated sites often pose a threat to drinking water wells.
Christ and Goltz have developed a semi-analytical algorithm that allows estimating the capture zones of extraction wells.
+
Christ and Goltz <ref name="christ2002">[http://dx.doi.org/10.1016/S0022-1694(02)00026-4 Christ and Goltz (2002)], J. Hydrology, p. 224-244 </ref> have developed a semi-analytical algorithm that allows estimating the capture zones of extraction wells.
A simple Matlab model was developed based on the semi-analytical solution from Christ and Goltz (2002)<ref name="christ2002">[http://dx.doi.org/10.1016/S0022-1694(02)00026-4 Christ and Goltz (2002)], J. Hydrology, p. 224-244 </ref>, which requires only a few parameters to estimate the capture zone of production wells with a given groundwater flow.
 
This can be very useful to get a quick estimate, if a contaminant is likely to flow towards a drinking water well, for example.
 
  
==== Required parameters ====
 
 
Following parameters are required to set up and run the model:
 
Following parameters are required to set up and run the model:
* Estimate of the hydraulic conductivity
+
* Estimate of the bulk hydraulic conductivity
 
* Average hydraulic gradient of the natural groundwater flow
 
* Average hydraulic gradient of the natural groundwater flow
 
* Reference head at one point in the domain
 
* Reference head at one point in the domain
* Direction of natural groundwater flow
+
* Direction of the natural groundwater flow
 
* Aquifer thickness
 
* Aquifer thickness
 
* Location of wells
 
* Location of wells
 
* Pumping rates of the wells in the study area
 
* Pumping rates of the wells in the study area
  
The model computes streamlines and isopotential lines for the given parameters.
+
The model computes streamlines and isopotential lines for the specified set of parameters.
When a background map of the study area is specified, the streamlines and isopotential lines are directly plotted on the map, as shown in the example below.
 
  
The semi-analytical solution is described in the paper by Christ and Goltz, J. Hydrology, 2002, p. 224-244.
+
This tool can be very useful to get a quick estimate of well capture zones to check, for example, if a contaminant is likely to flow towards a drinking water well.
[http://dx.doi.org/10.1016/S0022-1694(02)00026-4].
+
It does, however, not consider fracture flow and is based on several simplifying assumptions.
 +
When a background map of the study area is specified, the streamlines and isopotential lines can be directly plotted on the map, as shown in the example below.
  
A Matlab example file can be seen here:
+
A Matlab model was developed based on the solution from Christ and Goltz (2002) <ref name="christ2002" />.
 +
An example file for the larger Akacievej area can be seen here:
 
* [[ Matlab model Christ and Goltz | Matlab model for capture zone calculation]]
 
* [[ Matlab model Christ and Goltz | Matlab model for capture zone calculation]]
  
 
The example including the background map shown above can be downloaded as zipfile here:
 
The example including the background map shown above can be downloaded as zipfile here:
 
* [[:File:CaptureZones_MATLAB.zip|Download Matlab model]]
 
* [[:File:CaptureZones_MATLAB.zip|Download Matlab model]]
 
 
<!--
 
<!--
 
=== Leaching concentration profiles from a contaminant source (spreadsheet tool) ===
 
=== Leaching concentration profiles from a contaminant source (spreadsheet tool) ===
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=== Geologic modeling with GeoScene3D ===
 
=== Geologic modeling with GeoScene3D ===
 
[http://www.geoscene3d.com/ GeoScene3D] is a tool to import and work with borehole data to create a geologic model.
 
[http://www.geoscene3d.com/ GeoScene3D] is a tool to import and work with borehole data to create a geologic model.
It is possible to directly import data from the Danish borehole database [http://www.geus.dk/DK/data-maps/jupiter/Sider/data-dk.aspx Jupiter] and to interpolate borehole data, for example to obtain the surface of the top of the limestone.
+
It is possible to directly import data from the Danish borehole database [https://www.geus.dk/produkter-ydelser-og-faciliteter/data-og-kort/national-boringsdatabase-jupiter/ Jupiter] and to interpolate borehole data, for example to obtain the surface of the top of the limestone.
  
 
<references />
 
<references />

Latest revision as of 12:50, 3 July 2019

Highlights
  • Overview of modeling tools and software
  • Useful little tools and helpers
  • Spreadsheet tool for flow field under pumped conditions

Modeling tools

The following list shows some selected modeling tools that can be used for the simulation of fracture flow and transport.

COMSOL Multiphysics

COMSOL Multiphysics® is a comprehensive and flexible modeling suite that can be used to simulate various kinds of physics. It is well suited for computing flow and transport in limestone aquifers. It provides predefined physics-based interfaces (e.g. a module for subsurface flow) and allows equation-based modeling, where arbitrary partial differential equations can be solved. Different physics can be coupled, e.g., a flow model can be coupled with a transport model. The toolbox provides tools for geometry and mesh generation, a user interface for the simulation setup, several direct and indirectsolvers, and visualization and post-processing tools. It uses the finite-element method and includes higher-order discretization schemes.

For the modeling of flow and transport in porous media, there are predefined physics interface available. Fractures can be included as additional discrete features.

Another option is to use the PDE interface of COMSOL. The flow and transport equations are implemented as partial differential equations and the fracture flow and transport can be added using a feature called "Weak contributions". Here is an instruction file which describes how to setup a 2-dimensional flow and transport model including fracture flow and transport in COMSOL Multiphysics using the PDE interface.

FEFlow

FEFlow is a finite-element simulator focused on groundwater flow and transport of contaminants, groundwater age and heat in porous media. It comprises mesh generators, solvers and post-processing tools for visualization and result evaluation. It facilitates the computation of porous medium flow and transport in 2D and 3D aquifers, which can be confined, semi-confined or unconfined. Unsaturated flow can also be modeled with based on the Richards model. (Hydro-)geologic data can be easily imported and discrete fractures can be included.

TOUGH

DuMuX

  • DuMuX (free and open source)

Hydrogeosphere

Petrel

FRACGEN and NFFLOW

FRACMAN


Useful helpers

Besides the comprehensive models, there are several small tools available that can be helpful when dealing with contaminant transport in limestone aquifers. Some of them will be described in the following.

Example of capture zone calculations for the wells around the Akacievej site in Hedehusene. The blue lines are calculated streamlines and the green lines are simulated isopotentials.

Capture zone delineation of extraction wells (Matlab model)

Contaminated sites often pose a threat to drinking water wells. Christ and Goltz [1] have developed a semi-analytical algorithm that allows estimating the capture zones of extraction wells.

Following parameters are required to set up and run the model:

  • Estimate of the bulk hydraulic conductivity
  • Average hydraulic gradient of the natural groundwater flow
  • Reference head at one point in the domain
  • Direction of the natural groundwater flow
  • Aquifer thickness
  • Location of wells
  • Pumping rates of the wells in the study area

The model computes streamlines and isopotential lines for the specified set of parameters.

This tool can be very useful to get a quick estimate of well capture zones to check, for example, if a contaminant is likely to flow towards a drinking water well. It does, however, not consider fracture flow and is based on several simplifying assumptions. When a background map of the study area is specified, the streamlines and isopotential lines can be directly plotted on the map, as shown in the example below.

A Matlab model was developed based on the solution from Christ and Goltz (2002) [1]. An example file for the larger Akacievej area can be seen here:

The example including the background map shown above can be downloaded as zipfile here:

Spreadsheet tool for fracture transport based on the semi-analytical solution from West (2004)

Example for the evaluation of a slug test at the Akacievej site using the KGS model.

Hydraulic parameters from aquifer tests using Aqtesolv

Aqtesolv is an easy-to-use tool for the design and interpretation of aquifer tests like pumping tests and slug tests. It provides a variety of conventional solution methods for aquifer tests in confined, leaky and unconfined aquifers and several advanced methods, e.g. for fractured aquifers or oscillating water tables. A comprehensive description of the capabilities and a free demo version is available on the software's webpage. The software tool contains a comprehensive help menu that provides explanations of the different solution methods and the required parameters.

Geologic modeling with GeoScene3D

GeoScene3D is a tool to import and work with borehole data to create a geologic model. It is possible to directly import data from the Danish borehole database Jupiter and to interpolate borehole data, for example to obtain the surface of the top of the limestone.

  1. 1.0 1.1 Christ and Goltz (2002), J. Hydrology, p. 224-244

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