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


karunakar kintada, modified 3 Years ago.


Padawan Posts: 35 Join Date: 7/31/12 Recent Posts
Hi all,

First, i'm thankful to Deltares for making the solver open source. This certainly has changed the way people work on numerical modeling, freeing young scholars out of financial handcuffs and pull down till code, get an understanding of what they are doing. Innovative!.

Got a question and i shoot this one to tech team.

i'm working on mormerge and it is awesome technology. After working for quite a while, we realized that mormerge_alt script is easy to handle on windows, if files are sorted for repeated runs involving small changes. But the same procedure on linux is troubling, I would like to know if any such alt working script is available.
The model is based on Domain decomposition. Can the mormerge application spawn on multiple machines with online wave. The linux machine is a cluster based on CentOS and intel compilers, if one requires some information.
karunakar kintada, modified 5 Years ago.

RE: MorMerge

Padawan Posts: 35 Join Date: 7/31/12 Recent Posts
The DD model on linux cluster is slow according to the version update statements by deltares. So have to wait.
otherwise simple conversion of the (bat to sh) would do.
Adri Mourits, modified 5 Years ago.

RE: MorMerge (Answer)

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

"" is added in revision 5358.

I don't expect that mormerge will work when spawned on multiple machines. But with the script above it's easy to try: the lines starting a FLOW/WAVE executable should be started on other machines using ssh. Please report back on this forum if tried this.