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

SWAN Error

Lucas Pion, modified 3 Years ago.

SWAN Error

Youngling Posts: 12 Join Date: 5/7/13 Recent Posts

I am founding an error performing SWAN simulations and I was not able to solve it.
I have already created new versions of input files, changed folders, changed delft version for an older one that I have here and nothing worked.
The image attached shows more details of the error.

Has anyone seen something like that? Or knows what else it could be?

Thank you very much!
Adri Mourits, modified 2 Years ago.

RE: SWAN Error

Yoda Posts: 1212 Join Date: 1/3/11 Recent Posts

Hi Lucas,

Looking in the source code: it goes wrong when trying to create file "<runid>.swn", were <runid> is the base name of your mdw-file (e.g. if your mdw-file is named "test.mdw", then <runid> is "test"). Can you try to remove that swn-file from the working directory manually? Alternatively: what happens when you start with an empty working directory and copy all the input files in there, excluding the swn-file?