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

Running Stand-alone D-waves simulation on Delft Flexible Mesh

Christopher Mahlathi, modified 2 Years ago.

Running Stand-alone D-waves simulation on Delft Flexible Mesh

Youngling Posts: 4 Join Date: 10/25/17 Recent Posts

I have been struggling to set up at stand alone D_waves simulation on D-Flexible Mesh.

I have been able to set up a stand alone wave model, I have discovered the following.

•When I set up my model and with waves boundary condition settings: Wave Energy Density = Parametrized (constant) and a specified Time frame, the model runs without a problem. However,

•When I introduce my boundary condition in a form of a time series settings : Wave Energy Density = Parametrized (TimeSeries), and I copy the boundary time series to model Time point data, the model fails to run with the following error : Execution of Algoa_Waves has failed, External component has thrown an exception.

Are there any additional steps to follow when a time series boundary condition is used? is there any other way to introduce a time varying wave energy density data on my boundaries?

I understand that in SWAN we used a wavecon file, is there an equivalent for D-Waves Flexible Mesh?


CHristopher Mahlathi
Adri Mourits, modified 2 Years ago.

RE: Running Stand-alone D-waves simulation on Delft Flexible Mesh (Answer)

Yoda Posts: 1224 Join Date: 1/3/11 Recent Posts
Hi Christopher,

I'll forward your question with respect to Wave Energy Density to a colleague.

D-Waves does accept a wavecon file. The expected format is as in attached example file. I'm not sure whether the behaviour is the same as in SWAN. In case you want to try: when your mdw file is named "mytestcase.mdw", then the name of the wavecon file must be exactly "wavecon.mytestcase".

Defining a combined D-Waves - D-Flow FM testcase is delicate and not well documented yet. There is an example testcase in the trunk of the source code: