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

Fixed Weir Issue

Emma Nuss, modified 2 Years ago.

Fixed Weir Issue

Youngling Posts: 1 Join Date: 3/14/17 Recent Posts
Hi all,

I am having an issue with the addition of fixed weirs in a model configuration for a coastal estuary region with many small ponds with levees. It appears from my tests and what I've read in the technical manual, that the model will not run if the fixed weir points bisect a grid cell. When I remove the points that bisect any grid cells, the model runs fine, but I need to add in the levee features to represent the area correctly. Is there a way to edit the fixed weir points and snap them to the grid, so that they are aligned with the boundaries of the cell? Or any other potential solutions to this problem?

Your help is much appreciated, thanks!