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

error when running delft3D - flow

Hai Pham, modified 7 Years ago.

error when running delft3D - flow

dear every one!
I ask you for an error when i run Flow module of delft3D:

Invalid fist flux record on COM-file

have anyone know this problem and the way to resolve it? help me
Adri Mourits, modified 7 Years ago.

RE: error when running delft3D - flow

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

The most common problem is that a com-file is already present from a previous run while this is not intended. The solution is to remove the two files "com-<runid>.dat" and "com-<runid>.def" manually before starting the calculation.


Hai Pham, modified 7 Years ago.

RE: error when running delft3D - flow

Dear Adri Mourits,
I have followed your method and my model have run.
Thank you very much!