Dear FEFLOW user,

First of all, the FEFLOW team wishes all of you a Happy New Year 2009.

For FEFLOW, the new year starts with the release of FEFLOW 5.4, which is available for download from the FEFLOW website since before the holidays. The new license codes have already been sent to all DHI-WASY clients with a service and maintenance agreement (SMA). SMA clients of our different distribution partners will receive their codes soon from their respective distributor. The official release package with an updated User’s Manual and installation DVD is currently prepared and will be sent out soon, too. A list of new features is provided below.

We also would like to remind you once again that the deadline for abstract submission for the 2nd International FEFLOW User Conference (FEFLOW 2009) in Potsdam/Berlin in September 2009 is February 28. Below you find the basic conference information and a list of the keynote presentations and pre/post conference training courses.

Please have a look at our updated regular training program, too.

For any questions, suggestions, etc., please do not hesitate to contact us at!


What’s new in FEFLOW 5.4?


Here is an overview of the new features and improvements:

Borehole heat exchanger simulation

Many near-surface heat transport applications in FEFLOW deal with borehole heat exchangers. Previously these were either simulated in a fully-discretized way, leading to very detailed, but huge models, or only considering the net heat abstraction/injection via boundary conditions. While in the first case the simulation of larger arrays of heat exchangers is not feasible, the latter option might for example be oversimplifying the short-term processes when heat exchangers are run with changing input temperatures. With the new heat exchanger simulation option, heat transport in borehole heat exchangers can be simulated by a special 1-D element, calculating the heat transportin the pipes (u-shape, double-u-shape, or coaxial) and the transfer of heat via the grout into the surrounding underground.

Anisotropy of the heat conductivity

The heat conductivity of the solid can be made anisotropic by applying an anisotropy factor.

New SAMG solver without extra license

The algebraic multigrid solver package SAMG has been further improved and is now included in FEFLOW without the need for separate licensensing. The new version internally selects between a conjugent-gradient or algebraic multigrid solution for each time step, choosing the optimal solution strategy automatically.

Spline interpolation for parametric relationships in unsaturated flow

Alternatively to applying one of the pre-defined parametric relationships for unsaturated flow it is now possible to create user-defined relationships based on a list of data pairs and a spline-type interpolation between the points. A convenient editor makes it easy to input the data and to compare to the standard relations.

Parameter zones in FEFLOW Explorer

FEFLOW Explorer now supports plotting all data also onto parameter zones, i. e., bodies built from elements with like properties defined by a parameter interval. 

Elemental reference distribution for porosity values used for isochrone calculation

Isochrone calculations for pathlines are based on porosity to calculate real flow velocities. In previous FEFLOW versions, it was possible to use a constant porosity, the storativity parameter (specific yield), or - in transport simulations - the porosity for mass/heat transport for this. In confined flow models, for example, only constant porosity values could be used. Now an arbitrary elemental reference distribution can be alternatively chosen as the source of the porosity values, allowing a better isochrone calculation in pure flow models.

Output (simulation) times in different units

In alternative to the default simulation time output in days, different time units can now be selected (seconds, minutes, hours, days, years).

Pressure is available as a variable in the viscosity editor

In the viscosity editor used to define a user-defined relationship between temperature, concentration and viscosity now also pressure can be used as an input variable.

Improved parallelization

For operations performed for all elements, e.g., assebly of the matrix system, parallelization has been improved. With the new method, simulation runs can be better parallelized especially on machines with higher numbers of CPUs.

Grafic-less batch mode

While in previous versions of FEFLOW the graphical user interface was invoked even when using the -hide option in batch mode, it is now possible to use the simulation kernel without any graphical interface. For this, a separate command-line executable for FEFLOW is provided. This can speed up especially batch simulations with many small and fast-running models, avoiding the significant initialization time for the graphical interface.

Alternative search algorithm with spatial indexing

The alternative searching option with spatial indexing may speed up internal search functions in very large models, e.g., when doing pathline analysis or when using IFM functions that include element searches based on an X - Y - Z location. The option is available via the Quick Access Menu.

New IFM functions

Set transfer boundaries at single nodes with the transfer rate * area as a parameter:

IfmSetCoupledRiverBndNodes (IfmHandle, int, int*, double*, double*);
IfmSetCoupledMassTransBndNodes (IfmHandle, int, int*, double*, double*);
IfmSetCoupledHeatTransBndNodes (IfmHandle, int, int*, double*, double*); 

Enable/disable the spatial indexing:

IfmEnableSpatialIndex (IfmHandle hdl, IfmBool bEnableIndex);

Handle spline-based parametric relationships for unsaturated flow:

IfmGetSplineSaturationFunction (IfmHandle, int, IfmSpline*);
IfmGetSplineConductivityFunction (IfmHandle, int, IfmSpline*);
IfmSetSplineSaturationFunction (IfmHandle, int, const IfmSpline*);
IfmSetSplineConductivityFunction (IfmHandle, int, const IfmSpline*);


2nd International FEFLOW User Conference

September 14-18, 2009

Berlin, Germany

Download 2nd circular

The 2nd International FEFLOW User Conference, FEFLOW 2009, will mark the 30th anniversary of FEFLOW software. Since its first relase in 1979 as a purely scientific program, FEFLOW has undergone significant development over the years, making it today´s premium simulation software for subsurface and porous media modelling.
Building on the success of a series of previous FEFLOW user conferences, FEFLOW 2009 will feature numerous opportunities for exchanging ideas and improving your simulation skills. Highlights include:

·         Keynote presentations of trends and latest ideas in numerical modelling of water resources and related fields

·         User presentations showcasing the ways in which customers are using FEFLOW to solve challenging problems

·         Product updates

·         Opportunities to meet with DHI-WASY partners and FEFLOW users worldwide

·         Software demonstrations

·         Training courses (conducted on September 17 and 18)

It is our hope that many of you will be able to participate and to make the conference a beneficial event for all the participants.

The Organizing Committee

Key dates:

Abstract submission: February 28, 2009

Abstracts may be submitted to the Organizing Committee before January 31, 2009. Please email your abstract (up to 300 words) in MS Word format to, including information about author(s), organization(s), email address(es) and whether oral or poster presentation is preferred.

DHI-WASY will again award free FEFLOW licenses for the best oral and poster presentations.

Notification of acceptance of abstracts: April 1, 2009

Paper submission: July 31, 2009

Keynote Presentations

Prof. W. Kinzelbach
ETH Zurich

Real-time groundwater modeling

Prof. E. Frind
Waterloo University

Studies in well vulnerability: Land use optimization and model comparisons

Prof. P. Engesgaard
Copenhagen University

Coupled flow, mass, and heat transport at groundwater-surface water boundaries: Field observations and numerical modelling

Prof. C. Simmons
Flinders University

Variable density groundwater flow: From current challenges to future possibilities

Pre/Post Conference Training

(Sept. 10-12)


(Sept 14-16)

FEFLOW User Conference

(Sept 17)

Density-Dependent Modelling

Programming Interface IFM


(Sept 18)

Reactive Transport Modelling

Unsaturated Modelling

Upcoming training courses and workshops

Course Title






FEFLOW - Basics and Specific Applications



16-20 Feb 2009

Berlin, Germany

FEFLOW - Grundlagen und spezielle Anwendungen



30 Mar - 3 Apr 2009

Berlin, Germany

3rd FEFLOW Groundwater Modelling Course


Centre for Groundwater Studies (CGS)

21-24 Apr 2009

Perth, Australia

4th FEFLOW Groundwater Modelling Course


Centre for Groundwater Studies (CGS)

28 April – 1 May 2009

Sydney, Australia

Hands On FEFLOW Training course



19-21 May 2009

Shrewsbury, UK

FEFLOW - Basics and Specific Applications



22-26 Jun 2009

Berlin, Germany

A current list of all planned training courses and workshops can always be found on the FEFLOW training web page.

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