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

Cannot open .grd file in linux GUI

Mihael Souza, modified 5 Years ago.

Cannot open .grd file in linux GUI

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

I'm facing a problem I have no clue how to circunvent.
At first I was using Delft3D in Windows, since I was unable to install the GUI under Ubuntu.
I decided to give another shot at linux, and this time I was able to install the GUI following some discussion here on the forum and the install guide provided by Dan Nowacki:

The problem is, whenever I try to open an .mdf previously created (in windows, if it matters...), or to start a new .mdf, I don't seem to be able to load my .grd file in. I always get an error message saying that grid thickness is not 100%. My MDF's are all 2DH, so there should be no problem there. And, I can open my .grd file in RGF or Quickin. I just can't open it on the .mdf creation/editing. In windows, I can use it no problems.

Any ideas?


Mihael Souza
Mihael Souza, modified 5 Years ago.

RE: Cannot open .grd file in linux GUI

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

Just an update.
After reading this and this threads, I think the problem is how the GUI is recognizing your decimal characters in linux.
If I have a system set to recognizes the comma as decimal, the .grd import will crash with a "Thickness not 100%" error.
But opening up the .grd in a text editor and doing a replace all for the dots for commas, the import will work under the Flow Input menu. But, you will need to change it back before starting a computation, or opening the .grd file in RGFGrid or Quickin.

On the other hand, if you use a system in which the default decimal is the dot, you will not have any problems. At least, that is what happened once I changed my system from Brazil to the US pattern.

Hope this helps anyone facing the same problem.