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

bedload does not work as SedTyp in .sed file

Estelle Serrero, modified 4 Years ago.

bedload does not work as SedTyp in .sed file

Hi all,

I am having a problem with the "SedTyp" key word in the *.sed file for sediments. I can only import the file in the GUI when I enter the words "sand" or "mud" but not "bedload", even though I chose the non-cohesive option.

Does anyone know why and/or have a solution for this problem?

Adri Mourits, modified 4 Years ago.

RE: bedload does not work as SedTyp in .sed file (Answer)

Yoda Posts: 1221 Join Date: 1/3/11 Recent Posts
Dear Estelle,

I'm sorry, this is not supported by the Delft3D-GUI. This will be solved in the successor, DeltaShell, but that will take some time.

If you want to use the bedload sediment type, you will have to add that sediment type to the sed-file yourself using an ASCII editor. Here is an example data block:
   Name   = #Sediment 1#    [  -   ] Name as specified in NamC in md-file
   SedTyp = bedload         [  -   ] Must be "sand" or "mud" (or "bedload" fornon-constituent fractions)
   RhoSol = 2650.0          [kg/m3 ] Density
   SedMinDia = 0.000004     [  m   ] Sand only: Minimum sediment diameter
   SedMaxDia = 0.000032     [  m   ] Sand only: Maximum sediment diameter
   CDryB  = 1650.0          [kg/m3 ] Dry bed density
   SdBUni = 2183.0          [kg/m2 ] Initial sediment mass at bed per unit area  (uniform value or file name)