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

Error with Time series in Domain Decomposition models

Renan Pointeau, modified 5 Years ago.

Error with Time series in Domain Decomposition models

Youngling Posts: 5 Join Date: 5/12/15 Recent Posts

I'm having error when using Domain Decomposition with Time Series (I'm only using Flow). I haven't found any topics on this subject.

Tri-diag file says the velocities are going to high even in deep water (>100m depth), I tried to reduce my time step to fit with courant number, play with eddy viscosity and boundary reflection parameters without any success.

Water level with Harmonics are running fine but NOT with time series despite Water level time series are around zero.

It really looks like FLOW is having trouble to deal with Time series and Domain Decomposition...

I sincerely hope someone could help me.

Adri Mourits, modified 5 Years ago.

RE: Error with Time series in Domain Decomposition models

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

There is no known issue about DD in combination with Time Serie boundaries. Of course you must be careful when using time series on open boundaries that touch each other: if it doesn't "match", it will lead to strange results. But there is no link to DD.

Can you attach your model input to a post on this forum?

Thanks in advance.


Erik de Goede, modified 5 Years ago.

RE: Error with Time series in Domain Decomposition models

Youngling Posts: 13 Join Date: 1/7/11 Recent Posts
Dear Renan,

I would like to help you, but more information is needed for this.

To be sure, does your model with harmonic boundary forcing work well? Is the problem ONLY due to the time series boundary forcing?

Do you also have a single domain model with the time series boundary forcing? Does this give any problems? This will give insight whether you have to focus on the boundary forcing or on domain decomposition issues. Noted that domain decomposition and time series boundaries are (completely) independent issues. It is therefore unlikely that the combination of both causes the problem, as you suggests.

Hoping to hearing from you soon and with kind regards,

Erik de Goede