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 restart

Jacob Morgan, modified 4 Years ago.

simulation restart

Youngling Posts: 5 Join Date: 7/31/15 Recent Posts
I am attempting to restart a river simulation that I have previously run. I have both the restart file ( as well as the map-file (trim-A00_MASTER.dat and trim-A00_MASTER.def). When I attempt to use the restart file the simulation will begin from the correct time but the initial conditions of the bed elevations are apparently pulled from the depth file rather than the restart file. When I attempt to use the map-file the simulation fails before it begins and the tri-diag file reports: "*** ERROR Restart time not found on restart file trim-A00_MASTER.dat". Viewing the map-file in QUICKPLOT indicates that the restart time does occur in the map-file. The previous simulation and the one I am trying to begin are exactly the same except for the sediment supply rate. Is this somehow causing a problem? Do I need to change any of the input files other than adding "Restid = #trim-A00_MASTER#" to the .mdf file?

I would appreciate any help.

Adri Mourits, modified 4 Years ago.

RE: simulation restart (Answer)

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

The restart file does not contain bed levels, so that behaviour is as expected.

About using the map-file to restart from:
I managed to reproduce your error message by just adding the line "Restid = #trim-A00_MASTER#" to the mdf-file and nothing else. What you should do:
1. Be sure that the restart file and the current simulation have different runids, so if the mdf file is named "A00_MASTER.mdf" then rename the two trim files to something like "trim-A00_MASTER_previous.dat" and ".def" and use that as Restid specification.
2. Use for the current (new) simulation as starttime the endtime of the previous simulation.


Jacob Morgan, modified 4 Years ago.

RE: simulation restart

Youngling Posts: 5 Join Date: 7/31/15 Recent Posts
Good info, Adri!

I think my problem was a mix of the filename and the start time.

Thanks for your help!