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

RUN A NESTED DOMAIN independently (offline) of the overall domain

LUIS HENRIQUE SILVA, modified 7 Years ago.

RUN A NESTED DOMAIN independently (offline) of the overall domain

Youngling Posts: 12 Join Date: 9/30/11 Recent Posts

Hi Adri,

I am trying to run a nested domain independently (offline) of the overall domain,
but I was unsuccessful.

I did the normal nesting procedure, which are:
1) With NestHD1, and the input files

overall.grd and overall.enc
nested.grd and nested.enc

the files nested.adm and overall.obs were produced.
2) I run the overall domain using the overall.obs, and I got the outputs overall.trim and overall.trih.
3) With NestHD2, and input files overall.trih and nested.adm and nested.bnd the files nested.bct and nested.bcc
were produced.

Then I run the nested domain indicating overall.trim as initial condition (map-file) , and nested.bcc and
nested.bct as boundary conditions.

The model blows up in 2 or 3 times-steps. I noted that the fields in the time zero were not
the produced by the overall run. Also the undefined -999.0 seems to invade the simulation as true
values and contaminate the results.

Please, someone can help me, actually I do not know what is wrong with my procedure.


Luis Marton

Renan Ribeiro, modified 7 Years ago.

RE: RUN A NESTED DOMAIN independently (offline) of the overall domain

Padawan Posts: 55 Join Date: 3/23/11 Recent Posts
Hi Luis,

I think that you shouldn't indicate the trim-overall as a initial condition for nested model, probably these domains have different matrixes. Try to indicate a uniform condition for water level (the same you indicated for overall model).