intro story D-Flow FM


D-Flow Flexible Mesh

D-Flow Flexible Mesh (D-Flow FM) is the new software engine for hydrodynamical simulations on unstructured grids in 1D-2D-3D. Together with the familiar curvilinear meshes from Delft3D 4, the unstructured grid can consist of triangles, pentagons (etc.) and 1D channel networks, all in one single mesh. It combines proven technology from the hydrodynamic engines of Delft3D 4 and SOBEK 2 and adds flexible administration, resulting in:

  • Easier 1D-2D-3D model coupling, intuitive setup of boundary conditions and meteorological forcings (amongst others).
  • More flexible 2D gridding in delta regions, river junctions, harbours, intertidal flats and more.
  • High performance by smart use of multicore architectures, and grid computing clusters.
An overview of the current developments can be found here.
The D-Flow FM - team would be delighted if you would participate in discussions on the generation of meshes, the specification of boundary conditions, the running of computations, and all kinds of other relevant topics. Feel free to share your smart questions and/or brilliant solutions! 


We have launched a new website (still under construction so expect continuous improvements) and a new forum dedicated to Delft3D Flexible Mesh.

Please follow this link to the new forum: 

Post your questions, issues, suggestions, difficulties related to our Delft3D Flexible Mesh Suite on the new forum.





Sub groups
D-Flow Flexible Mesh
Cohesive sediments & muddy systems


Message Boards

Open Source DEFLT3D Engine vs Licensed DELFT3D

Dadiyorto Wendi, modified 9 Years ago.

Open Source DEFLT3D Engine vs Licensed DELFT3D

Youngling Posts: 1 Join Date: 1/12/12 Recent Posts
Hi there,

We are interested in using DELFT3D. Could I get information on the following,

a) The difference between the DELFT3D engine based on open source and the licensed one.
b) The price of the licensed DELFT 3D engine.

Thank you for the help.

Bert Jagers, modified 9 Years ago.

RE: Open Source DEFLT3D Engine vs Licensed DELFT3D (Answer)

Jedi Knight Posts: 201 Join Date: 12/22/10 Recent Posts
Hi Dadiyorto,

a) The difference between the DELFT3D engine based on open source and the licensed one.

We build the Delft3D-FLOW and WAVE executables included in Service Packages from the source code that is available in the open source repository; there are no secret features included, so basically there is no difference. However, after building the source code, we run a lot of test simulations to verify the correctness of the new executable. This test bed includes many simple and complex models from previous project by Deltares and clients, and hence it contains proprietary information and thus it can't be provided to the community. So, you won't be able to do the same amount of rigorous testing.

If you use the trunk to build your own Delft3D executables, you will sometimes obtain stable versions and sometimes buggy unstable ones. However, if you build your own Delft3D executables from the tagged branches, then you have a fair guarantee that it's a stable version: the source code was tagged because the executables that we built from it, passed most of our tests. However, since you may be using a different compilation environment, your executables may differ slightly from the ones we tested and hence there is no formal guarantee that the executables that you've built work equally well. This may be OK for a research application, but may be not enough for operational or consultancy applications.

b) The price of the licensed DELFT 3D engine.

The Hydro-Morphodynamics Basic Service Package is priced at just 2925 Euros (price level of 2011 and 2012; no restrictions with respect to model size, number of concurrent simulations, etc). This includes 8 hours of support and free updates during the year. There are other service packages that include water quality, ecology and particle tracking, and/or higher levels of support. See for details the Service Packages pages on the Deltares systems site. Note that for universities the Full Basic Service Package that includes all Delft3D modules is available for this same price; which is especially a good deal on Windows on which platform you otherwise will have to buy both Visual Studio and Intel Fortran to compile the software yourself.

Best regards,