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

RGFGRID Crashes When Merging Irregular Grids - MATLAB Alternative?

Robert Jenkins, modified 1 Year ago.

RGFGRID Crashes When Merging Irregular Grids - MATLAB Alternative?

Youngling Posts: 11 Join Date: 7/28/15 Recent Posts

Hello all,

I am having terrible difficulty merging 2 irregular grids in RGFGRID using the methods described in the manual and webcasts. These grids have nodes & links exactly coinciding in the area where I need them to connect. It appears that the second grid is simply too large for RGFGRID to handle. I am currently getting an error which states "Map Frontend Application has Stopped Working" (RGFGRID

 Are there any openearthtools for MATLAB which can handle the merging? I am able to read both grids fine with "dflowfm.readNET" but I have no method to combine the nodes, the links, and then to write them to an file.


"dflowfm.writeNET" writes the combined nodes but doesn't seem to handle the links as I have tried combine them.