• Background maps (ASCII, ArcInfo Generate, ArcView Shape, DXF, TIFF, HPGL)
• Use of maps as basis of mesh generation and spatial distribution of material properties, initial and boundary conditions.
• Georeferencing of maps in FEMAP (inclusive), extended functionality (coordinate transformation etc.) in WGEO
• fully or partly automatic mesh generation offering different generation algorithms
• Boundary conditions of 1st, 2nd and 3rd kind as well as specific well boundary condition allowing multilayer wells.
• physical constraints to boundary conditions using 'constraint conditions'
• Input of material properties with the aid of different interpolation routines for imported ASCII or GIS data (Kriging, Akima, Inverse Distance Weighting, Linear 1-D)
• time-dependent boundary conditions, constraint conditions and material properties
• easy to use expansion of 2D to 3D models employing the 3D layer configurator.

General

• Steady-state or transient simulation
• Different time-stepping methods:
  • constant time steps
  • varying pre-defined time steps
  • fully automatic time-stepping procedure using predictor-corrector or aggressive target-based schemes
• Different approaches for free surface calculations:
  • moving meshes
  • linearized relationship for the saturation vs. relative conductivity curve with residual water depth
  • fully unsaturated modeling
• Automatic calibration 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, separate package)

• interactive 3D rotation and zoom
• 3D view of the model area (finite element mesh, material properties, computed distributions) with isolines, 3D isosurfaces, cross sections etc.
• 2D view with isolines, velocity vectors, background maps, etc. as a vertical cross section or horizontal projection
• particle tracking with isochrone markers
• steady-state or transient
• 2D or 3D
• extensive export functions: vector graphics (ESRI Shape File, DXF, FEFLOW Plot File, ASCII), screendumps, data triplets/quads, diagram points, etc.
• creation of plot layouts with extensive additional features (background maps, legends, frames, text, etc) in FEPLOT for Windows (inclusive)
• analysis of results in every time step as well as differential operations
• comparison with reference data and distributions
• creation of mass and energy balances for the model area or parts of it using the 'budget analyzer'
• computation of flux through cross sections or single layers using the 'fluid flux analyzer'
• Free FEFLOW Explorer for 3D visualization, animation and video export of FEFLOW model properties and simulation results

• Linear (Bear-Scheidegger) or nonlinear dispersion
• Sophisticated upwind techniques:
  • Galerkin-FEM
  • Streamline upwinding
  • Shock capturing
  • Least-square upwinding
  • Full upwinding
• Parameter fitting for the sorption isotherms in FE-LM² (included)
• Density-coupled modeling for concentration-dependent fluid density and fluid viscosity (e.g. for salt water intrusion problems)
• Simultaneous modeling of heat and mass transport (thermohaline transport)
• Forward or backward transport modeling (reversed flow field)

Single-species transport

• Decay processes:
  • Reactions of 1st order
  • Michaelis-Menten reactions
  • radioactive decay (decay chains) using an external module
• Consideration of equilibrium sorption according to the
  • Henry
  • Freundlich
  • Langmuir isotherms

Multi-species reactive transport

• Arbitrary number of chemical species
• Dissolved or sorbed species
• Definition of arbitrary chemical reactions via reaction kinetics editor

• Heat conductance and storage in the fluid phase
• Heat conductance and storage in the matrix
• User-defined heat transport parameters of fluid and matrix
• Density-coupled modeling for temperature-dependent fluid density and fluid viscosity
• Simultaneous modeling of heat and mass transport (thermohaline transport)

• Consideration of variable saturation, i.e. unsaturated and saturated zones in one model
• Different paramter models:
  • van Genuchten
  • Brooks-Corey
  • van Genuchten modified (variable m)
  • Haverkamp
  • Exponential
  • Linear
• Different forms of Richards' equation
• Consideration of capillary hysteresis
• Parameter fitting for different parameter models in FE-LM² (inclusive)

• Study of pollutant dispersion
• Evaluate remediation and decontamination strategies
• Study of groundwater drawdown and rise in mining areas
• Mine dewatering studies
• Survey of saltwater intrusion
• Isotope calculation for detection of groundwater age
• Design of geothermal power plants (HDR, heat pump systems)
• Coupled groundwater/surface water simulation via online linking with MIKE-11 and Hydro_AS-2D (by M. Nujic)
• Geotechnical applications (tunnel construction, construction site dewatering)
• Calculation of dam seepage
• Soil-colmn calculations
• Infiltration calculation
• Assessment of availability of groundwater resources
• Estimation and control of strategies for groundwater management
• Design of well-head protection zones
• Studies for environmental impact assessments
• Design of groundwater monitoring programs
• Applications in research

For extending the capabilities of FEFLOW, its open programming interface IFM offers nearly unlimited possibilities.