FEFLOW
Flow and transport of dissolved constituents and/or heat transport modelling
- A completely integrated system from simulation engine to graphical user interface
- Pre- and post processing ability, an efficient simulation engine
- Includes a public programming interface for user code
Overview
Short Description
- Professional software package for modeling fluid flow and transport of dissolved constituents and/or heat transport processes in the subsurface.
- Contains pre- and post processing functionality and an efficient simulation engine. A user-friendly graphical interface provides easy access to the extensive modeling options.
- It is a completely integrated system from simulation engine to graphical user interface. It includes a public programming interface for user code.
Applications
FEFLOW is suitable for numerous different applications in flow and transport processes simulation in porous media, ranging from lab scale to continental scale. A few typical examples are listed here:
- Groundwater Management
- Geothermal Energy (Deep and Near-Surface)
- Mine Water Management
- Geotechnical Applications
- Industrial Porous Media Design
- Survey of Saltwater Intrusion
- Study of Pollutant Dispersion
- Coupled Groundwater/Surface-Water Simulation (Linkage with DHI MIKE11)
For extending the built-in capabilities of FEFLOW, its open programming interface IFM offers nearly unlimited possibilities.
Benefits
Flexible mesh generators
Finite-element discretization allows to use complex unstructured meshes that closely match natural structures while obeying requirements such as element size, element angles, etc..
Parallel computing
Transient calculations of complex regional models for long time periods require significant computational effort. Parallel processing allows a significant reduction in CPU times on multiple-processor platforms.
Finite-element method
Classic groundwater simulation codes use finite difference discretization. In contrast, FEFLOW is based on the finite-element technique.
Major advantages of finite-element modeling include:
- Unstructured meshing, thus much better representation of features like rivers, fractures, well locations by adaptation of the mesh
- Less computational effort due to reduced element numbers for large regional models
GIS/CAD interface
In most practical applications, the basic spatial data are available either in GIS (e.g., ESRI formats) file format or in a CAD-like format (e.g., AutoCAD exchange format). Direct import of these data formats helps to avoid intermediate conversion routines for transferring the basic data to the groundwater model.
Up-to-date visualization tools
Using FEFLOW three-dimensional visualizations of all model parameters and modeling results (like movements of contaminant plumes, etc.) can be produced.
Sophisticated solvers
To guarantee both stability and effectiveness of the solution, highly sophisticated solvers are required. In FEFLOW, sparse-matrix PCG-type solvers as well as an algebraic multigrid solver are available.
Open Programming Interface
For such cases FEFLOW provides an open programming interface to interact with user-specific additional plug-ins. Parameters can be changed at any time, boundary conditions can be varied using external dependencies, time stepping can be influenced, even other programs (like hydrodynamic simulation or parameter estimation software) can be directly linked to FEFLOW.
Physical Processes
Groundwater Flow
FEFLOW provides a flexible environment to represent different kinds of groundwater flow systems:
- 2D horizontal or cross-sectional projection, 3D representation
- Confined, partially confined or unconfined conditions
- Different ways of handling phreatic surfaces
- Boundary conditions of 1st, 2nd and 3rd kind as well as specific well boundary condition including multilayer wells
- Physical constraints to boundary conditions
- Time-dependent material properties, boundary conditions and constraint
- Definition of selected parameters (e.g., groundwater recharge) by applying a user-defined equation
- Possibility to couple groundwater (FEFLOW) and surface water (MIKE 11) flow simulation
Solute Transport
FEFLOW can simulate single-species and reactive multi-species solute transport in groundwater and the unsaturated zone, including sorption and chemical reactions:
Decay and sorption
- Decay processes: 1st order decay or Michaelis-Menten reaction
- Equilibrium sorption: Henry, Freundlich, or Langmuir isotherm
Multi-species reactive transport
- Arbitrary number of chemical species
- Dissolved or sorbed species
- Definition of arbitrary kinetic reactions via equation editor
General mass-transport features
- Sophisticated upwind techniques
- Parameter fitting for the sorption isotherms in FE-LM² (included)
- Density-coupled modelling for concentration-dependent fluid density and fluid viscosity (e.g. for salt water intrusion problems)
- Simultaneous modeling of heat and (single- or multi-species) mass transport
- Forward or backward transport modeling (reversed flow field)
- Linear (Bear-Scheidegger) or nonlinear dispersion
Heat Transport
With its capabilities to simulate flow and heat transport in the subsurface, FEFLOW is the ideal tool for modeling geothermal energy systems and other thermal processes in groundwater.
- Consideration of borehole heat exchangers via an efficient one-dimensional implementation
- Plug-ins for frequently needed applications in the geothermal energy sector
- Density- and viscosity-dependent flow processes
- Simultaneous modeling of heat and (single- or multi-species) mass transport
Modeling of Unsaturated Conditions
FEFLOW can simulate unsaturated and variably saturated conditions in 2D and 3D by using Richards' equation in combination with a parametric model for the saturation vs. pressure head and saturation vs. relative conductivity relationships.
- Flexible parameter models (also combinations):
- van Genuchten, Brooks-Corey, van Genuchten modified (variable m), Haverkamp, Exponential, Linear, Spline interpolation of tabular data
- Different formulations of Richards' equation (head based, mixed, and variable substitution form)
- Different numerical schemes
- Consideration of capillary hysteresis if required
- Parameter fitting for different parameter models in FE-LM² (inclusive)
Fracture Modeling
Preferential flow paths, such as fractures, drains, boreholes and mine voids, can be taken care of by applying so-called Discrete Feature Elements, i.e., one- or two-dimensional finite elements within two- or three-dimensional FEFLOW models.
- Flow calculated using Darcy's law, Hagen-Poiseuille cubic law, or Mannings equation
- Solute and heat transport in Discrete Feature Elements
- Additional sources and sinks
Density-dependent Simulation
Density and viscosity differences may influence groundwater flow systems significantly, e.g., in coastal regions or when dealing with geothermal systems. FEFLOW provides a maximum of flexibility for these purposes by density-dependent flow simulation, viscosity-dependent flow simulation etc.
- Density-dependent flow simulation
- Viscosity-dependent flow simulation
- Concentration-dependent density and viscosity
- Different influence of multiple chemical species on fluid density
- Temperature-dependent density and viscosity
- Editable relationships for density and viscosity
Features
Model Design
The model setup process in FEFLOW is quick and efficient:
- 2D and 3D map support (ASCII, ESRI Shape, DXF, TIFF, JPG, PNG, ...)
- Map geometries and data used for mesh design and parameterization
- Regionalization from point, line, and polygon data
- Georeferencing of maps and general geoimaging in WGEO (license included)
- Flexible automatic mesh generation based on sophisticated algorithms supporting local refinement
Simulation
The simulation needs to be accurate and efficient for all relevant cases:
- Steady-state or transient simulation
- Different time-stepping methods (constant, varying pre-defined, fully automatic procedure using predictor-corrector or aggressive target-based schemes)
- Different approaches for free surface calculations (moving meshes, linearized relationship for saturation vs. relative conductivity curve with residual water depth, fully unsaturated modeling)
- Parameter estimation tool on base of PEST (by J. Doherty)
- Efficient control of the simulation process with customizable real-time diagrams for all important model results
Solvers
- Newton and Picard iteration techniques for nonlinear problems
- Fast iterative and direct solvers like PCG and Restarted-OR-THOMIN with powerful preconditioners
- Alternatively algebraic multigrid solver (SAMG by K. Stueben)
Analysis
Analysis and postprocessing features are crucial for calibration and results evaluation. FEFLOW provides easy-to-use tools and visualization options:
- Diagram windows for observation wells
- Export of model parameters and results as values, vector plots and images
- Budgeting of water, solute, and heat flows for the model domain or parts of it
- Particle tracking with isochrone markers (steady-state or transient, 2D or 3D view)
Visualization
Up-to-date visualization tools - including animations - support the presentation of modeling results to the client and the public. On the other hand, for complex large models, visual perception of all aspects of the model is also strictly required from the point of view of the modeler while editing input data and analyzing simulation results. FEFLOW provides:
- Bird's eye and cross-sectional views
- 3D view
- 2D and 3D map support
- Arbitrary combination of model parameters, maps, and visualization styles in each view
- Clipping and carving
- Isolines, filled contours, continuous plots, vectors. isosurfaces, streamlines, pathlines, ...
- Image export in different formats and with customizable resolution
- Animation and video export
- Live visualization of current results during simulation
The free software FEFLOW Viewer provides all visualization and postprocessing capabilities without requiring a license for FEFLOW.
Programing Interface IFM
The open programming interface IFM provides the possibility to easily extend the standard capabilities of FEFLOW by user-defined functionality.
A number of call-backs in the FEFLOW code can be used to execute user code at specific stages of the modeling process, e.g., whenever the model file is opened or after each time step of a transient simulation. The second component of the interface - a large number of FEFLOW-specific functions - can be used to access nearly all model data in FEFLOW for reading and writing.
Plug-ins for the programming interface are typically programmed in C or C++, external code in other languages can be used via mixed-language programming. The generation of all necessary frame code is conveniently done by a plug-in for Microsoft Visual Studio, thus limiting the required programming skills of the user to the complexity of the specific functionality to be implemented.
A broad variety of plug-ins for the programming interface is already available on demand, and plug-ins are also shared widely within the FEFLOW user community.
Feature Levels
FEFLOW is available in 4 different feature levels
| Groundwater Flow | Mass Transport | Heat Transport | |
|---|---|---|---|
| FEFLOW F3 |  | ||
| FEFLOW FM3 | | | |
| FEFLOW FH3 | | | |
| FEFLOW FMH3 | | | |
Each level includes the program features of all lower levels. Groundwater-age simulations require a license for mass transport.
License Type Comparison
| Essentials FMH3* | Professional FMH3* | |
|---|---|---|
| |
Groundwater Flow |
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FePEST |
| |
Age Calculation |
| |
Heat Transport |
| |
Solute Transport |
| |
Multispecies Transport |
| |
Borehole Heat Exchangers |
| |
Unsaturated / Variably Saturated Flow |
| |
Discrete Fractures |
| |
Cross-sectional / Axisymmetric Modeling |
| |
Rotation of Gravity Vector |
| |
Element Deactivation |
| |
Plug-in Use |
|
Network License Management |
|
|
License Sharing for Similar Models |
|
| unlimited | unlimited | Modell Size |
| |
Physical Delivery (Software/Manuals) |
| |
Download Delivery (Software/Manuals) |
* Lower feature levels available.
Licensing
Choose the most appropriate licensing option for your needs
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- - - - NO Switch between licences - - - -
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System requirements
Operating Systems
Windows:
Fully supported Windows versions
- Windows 7 Professional Service Pack 1 (64 bit),
- Windows 10 Pro (64 bit),
- Windows Server 2012 R2 Standard (64 bit) and
- Windows Server 2016 Standard (64 bit)
Not supported, but partially tested Windows versions
- Windows 8.1 Pro (64 bit) and
- Windows Server 2008 R2 Standard Service Pack 1 (64 bit)
Linux:
- DEB packages for Debian and Ubuntu 12.4+
- RPM packages for SUSE 12.2+ and Red Hat and CentOS 7.0+
Processor:
- 64 bit and >= 2.2 GHz
Graphics:
- Full HD (1920 x 1080) resolution
- Graphics adapter: >= 2 GB memory, >= 24 bit colour, Shader version >= 1.30
Memory:
- >= 4 GB
Hard Disk:
- >= 5 GB free space on the hard drive