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

Fully coupled flow+wave model with nesting?

arun svv, modified 1 Year ago.

Fully coupled flow+wave model with nesting?

Youngling Posts: 11 Join Date: 4/22/15 Recent Posts

Hi All,

I have a query on coupled flow+wave model. From the flow and wave manuals and from the delft dashboard tutorial, I'm clear that we can perform coupled modelling of flow and wave modelling. In my case, I've configured a coarser domain (overall) with tidal boundaries (astronomic) at all the three boundaries for flow model (one is the land part) and WW3 output data for the wave model. The online coupling has been used. Model is successfully running without any problem.

However, I have another smaller domain (with high-resolution grid) within the overall model domain. I want to perform the same "coupled flow+wave" in the smaller domain also. The smaller domain has an orientation of 45 degrees.

Wave manual says for wave modelling nesting can be used. Whereas, the flow model environment doesn't have that option. Instead, we should either use "Domain decomposition" - for parallel running or Nesting (in offline mode), where I need to run the overall model first and extract the "bct file" to give as the boundary condition for the smaller domain.

I'm interested to use the coupled model in overall as well as fine resolution model domains. Is there any way to do that?

Presently, I've configured the overall model (flow+wave) with wave nesting option. So, I'm able to get the water levels and depth-averaged tidal currents for the coarser domain and waves for both coarser and finer domain.

Now I can extract the overall model boundary conditions and give as inputs to the flow model only. But I don't know how to extract waves from an overall domain as the boundary condition for the smaller domain.


Can someone help me in solving it?


best regards





Christian Orta, modified 8 Months ago.

RE: Fully coupled flow+wave model with nesting?

Youngling Posts: 2 Join Date: 10/28/19 Recent Posts
Arun ,I have the exact same question, did you manage to solve it?Regards Chris
Nora Asa, modified 6 Months ago.

RE: Fully coupled flow+wave model with nesting?

Youngling Posts: 6 Join Date: 11/20/19 Recent Posts
<p>Hi Arun and Christian, I have the same problem. I don&#39;t know how to transfer wave data from the coarse domain to the nested domain. Would you let me know if you manage to figure it out? Best, Nora</p>