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 D3D version 5 and version 6 on same machine

Ben Williams, modified 7 Years ago.

Running D3D version 5 and version 6 on same machine

Jedi Knight Posts: 114 Join Date: 3/23/11 Recent Posts
Hi D3D people,

Is it possible to have two versions of Delft3D peacefully cohabiting on the same Windows machine? For legacy reasons I am using Delft3D version 4.x and 5.x, which are compatible with GUI 4.00.02 (and lower). However for various reasons I also need to use the newer version (6.x) of Delft3D with the water quality module attached, which is only compatible with GUI 4.01.00

Is it possible to have both installations on the same machine and not have all sorts of headaches? I would try just having two W32 folders and then just renaming them as required, but occasionally I need to run simulations from the 'new' version and 'legacy' version at the same time.

Kind regards,

Mihael Souza, modified 7 Years ago.

RE: Running D3D version 5 and version 6 on same machine

Padawan Posts: 65 Join Date: 10/11/12 Recent Posts
Hi Ben,

Actually, if you use revision 2367 under the tagged versions from delft, you have a fully available model (FLOW + WAVE + WAQ).
As I understand and have been previously commented by Adri, this revision passed both the FLOW and WAVE test bench.
That way, you can use only version rc03 of the GUI (newer GUI available for download).

If, by some reason, you do need to use version 5.xx and older of the FLOW model, than I suppose you can use both versions at the same time.
As I understood, by trying an error myself, only the previous GUI is formerly installed on your PC.
The newer one abandoned the old format of the w32 folder, replacing it for the use of win32 and what appears to be a batch file to open up the GUI (sorry if batch file is the wrong description, I'm not very experienced with Windows file formats).
I had both GUIs installed on my notebook previously, and had no problems with either of them in terms of usage.
But, I had not tested running a simulation, so that much I can't guarantee you.

Hope this helps!

Kind regards,

Mihael Souza.
Adri Mourits, modified 7 Years ago.

RE: Running D3D version 5 and version 6 on same machine

Yoda Posts: 1221 Join Date: 1/3/11 Recent Posts
Hi Ben and Mihael,

Having installed different Delft3D versions in different directories:
  • Before using GUI 4.00.03 and older, you have to check that environment parameter "D3D_HOME" is pointing to the version you want to use.
    "Start"-> Control Panel -> System -> Advanced System Settings -> Environment variables...
    Or use a batch file like "d3d_menu.bat" mentioned at the next bullet:
  • GUI 4.01.00 and higher works fine; the menu is started by executing "d3d_menu.bat". You can check that environment parameter "D3D_HOME" is set dynamically in this shell.

When doing a FLOW calculation, always check that the version number being echoed in the tri-diag-file is as expected.