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

Simulation crashed. How to continue from where it stops?

Anas Rahman, modified 6 Years ago.

Simulation crashed. How to continue from where it stops?

Youngling Posts: 21 Join Date: 10/4/13 Recent Posts
Hello everyone,

I was running a long flow simulation in Linux (approximately 30 days to finish the computation). Then the simulation crashed at about 60%. I am not yet sure whether it was caused by the system or the software

Does anyone know how I can continue from where it stopped? I really hope I am able to resume the simulation, and not to start all over again if possible.

Thank you !

Mihael Souza, modified 6 Years ago.

RE: Simulation crashed. How to continue from where it stops? (Answer)

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

Did you define the creation of restart files during your simulation? If so, in the Delft3D directory there should be a bunch of tri-rst files. These files have the time stamp on them, so you know in which part of the simulation they were created. If you want, you can update the start time in the MDF to match one from a tri-rst file, and in initial conditions choose to use a Restart file. This will resume your simulation from that point on.

If you want to know if the simulation crashing was due to a system or model error, take a look at the tri-diag files. If any instabilities provoked the crash, it will be written in there. This could at least give you an indication with the problem was on your simulation.

Kind regards,

Adri Mourits, modified 6 Years ago.

RE: Simulation crashed. How to continue from where it stops?

Yoda Posts: 1221 Join Date: 1/3/11 Recent Posts
Hi Anas,

One addition to Mihael's answer: you can also restart using a map-file. See the manual, section "4.5.5 Initial conditions".