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

Post Processing with Python

Justin Pringle, modified 3 Years ago.

Post Processing with Python

Youngling Posts: 2 Join Date: 1/23/12 Recent Posts
Hi All,

I would like to use python to handle my post processing. I understand that DELFT3D uses the nefis file storage system. I have also located a nefis python module on pypi however it comes with no documentation. This makes it incredibly difficult to use, furthermore the python module does not appear to contain the functions described in the nefis manual? Can someone kindly provide assistance?

Thanks in advance
Andrea Cimatoribus, modified 3 Years ago.

RE: Post Processing with Python

Youngling Posts: 4 Join Date: 3/8/16 Recent Posts
Your best solution is probably to use netcdf files as output. You can do that by adding the following keyword in the mdf:
FlNcdf = #maphisdrofou#
Davi Carneiro, modified 3 Years ago.

RE: Post Processing with Python

Youngling Posts: 8 Join Date: 9/25/14 Recent Posts
And how about the DELFT3D WAVE module?

I've been using this netcdf functionality for the FLOW model, but now I will need to read the nefis files from Fortran or Python concerning the wave map files since I haven't found any similar solution.

The Python nefis library is made for Windows but since I am working mainly on Linux and trying to setup an operational system I will need to make further development with Python or use Fortran. I will keep you posted about my progress.
Dmitry Kushnir, modified 3 Years ago.

RE: Post Processing with Python

Jedi Knight Posts: 102 Join Date: 11/9/12 Recent Posts
Hi Davi,

Thanks for your post. I'm looking forward to reading about your progress on this.

Previously, I considered an option to compile a newer version of the SWAN, which supports netCDF-output, for coupling it with Delft3D-FLOW.
I haven't implemented that so far.It might well be a headache task.