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

3D gate

Aleksandr Semchukov, modified 4 Years ago.

3D gate

Youngling Posts: 13 Join Date: 5/28/15 Recent Posts
Hello. I am new here, so I hope that you would apologize me for the stupid question.

According to the 3D gate input file structure (B.3.1 section of the Delft3D-FLOW manual), the layer numbers over which the gate extends must be specified. But in the sigma-model the layer height varies during simulation. Does this stands for the gate height would also vary? I have fo?nd no information about it in the manual.

Thank you very much for assistance.
Qinghua Ye, modified 4 Years ago.

RE: 3D gate (Answer)

Jedi Council Member Posts: 612 Join Date: 3/2/11 Recent Posts
Hi Aleksandr,

According to the Delft3D-FLOW Manual and discussion with colleagues, you are right that, when you use 3D gate, the layers are specified. Thus yes, the gate is varying in theory during the simulation. This implementation might lead to unrealistic results sometimes.

You might use the Current deflection wall (CDW), where you can specify the exact z position.

Hope this helps,

Aleksandr Semchukov, modified 4 Years ago.

RE: 3D gate

Youngling Posts: 13 Join Date: 5/28/15 Recent Posts
Thank you very much, Qinghua. Your information is very usefull. I thought it was possible to fix the gate height by some switch in the input file.