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

Definition of History Output (for Fluff Layer)

Roland Hesse, modified 4 Years ago.

Definition of History Output (for Fluff Layer)

Youngling Posts: 19 Join Date: 11/21/14 Recent Posts
Dear all,

currently, I am using Delft tag 5656 (64bit). In the relase notes, it is stated for fixed bugs since tag 5169: "Information of fluff layer is now written correctly to the map- and his-file". Unfortunately, the fluff layer information (e.g. 'available mass in fluff layer') only appears in the trim-file (map).

Does anyone know why this might happen? Is there an additional/ alternative way to specify the history (trih-<...>.dat) output? I am aware of the keywords in the mdf-file (shhydr = #YYYY# shderv = #YYYYY# shproc = #YYYYYYYYYY# shflux = #YYYY#).

Thank you in advance, kind regards

Adri Mourits, modified 4 Years ago.

RE: Definition of History Output (for Fluff Layer) (Answer)

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

The conditions for writing fluff information to the his-file are identical to writing to the map-file: there must be at least one sediment type specified and the fluff layer must be specified. You can not influence it with the mdf-keywords you mentioned.

To check whether this is a FLOW problem or a postprocessing problem: can you check whether the data is present on the his-file using the tool "VSI"? It's available in the Delft3D-GUI utilities. Group "his-sed-series" in the his-file should contain parameter "MFLUFF".