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


Abdulla Mohamed, modified 5 Years ago.


Youngling Posts: 16 Join Date: 6/12/13 Recent Posts
Is is possible to run the overall model and the nested refined model together at the same time?
From my understanding (and am pretty new to Deft3D) of reading the manual the steps for nesting would be :
1. Make the smaller model grid for nesting
2. Get the boundary locations around the small gird for extracting the boundary conditions from the overall model using NESTHD1
3. Run the overall model with these locations added as observation points
4. Run NESTHD2 with the history file to make the boundary conditions file
5. Run the small model with these boundary conditions file

I guess my question would be is there a way to combine 3,4 and 5 to run the overall model and the nested model at the same time?

Thanks for all your help.

Guoxiang Wu, modified 5 Years ago.

RE: Nesting

Youngling Posts: 16 Join Date: 8/20/11 Recent Posts
I think you can try Domain-Decomposition technique, which is more like a two-way online nesting.