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

Problem running Delft3D-Flow in parallel mode

Stephanie Zeunert, modified 6 Years ago.

Problem running Delft3D-Flow in parallel mode

Youngling Posts: 14 Join Date: 6/2/14 Recent Posts

I'm currently having trouble running Delft3D in parallel mode.I recently installed a version of Delft3D on a Linux cluster computer as specified on your webpage
"". Although we were able to start the program on one node with one core, it failed when we tried multiple cores or even multiple nodes. We always got the fortran runtime error, that the file "td-diag" already exists. The technicians maintaining the cluster computer now tell me that DELFT3D requires MPICH2 while the computer uses openMPI and that the only way to make parallel processing work is by altering the source-code.
My question now is, is there an easier way to enable parallel processing on openMPI, or will openMPI be supported in a future version? If there is, how can I change the example script to make it work?

Thanks, Stephanie
Adri Mourits, modified 6 Years ago.

RE: Problem running Delft3D-Flow in parallel mode (Answer)

Yoda Posts: 1221 Join Date: 1/3/11 Recent Posts
Hi Stephanie,

The executables you obtain when having a service package are indeed using mpich2. When you compile the code yourself, you can choose to use openMPI instead of mpich2. Some users managed to do so; check the forum.
Some remarks if you are going to do this:
- Use the latest tagged version, currently
- You have to use an openMPI version that is compiled with exactly the same compiler as you use for Delft3D. Check that you refer to the correct version during compiling
- Check the FAQ and the forum in case of problems

Producing a Delft3D-FLOW version based on openMPI is not planned yet.