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

Boundary Flags

Robert Jenkins, modified 4 Years ago.

Boundary Flags

Youngling Posts: 11 Join Date: 7/28/15 Recent Posts
Are there currently any under-development tools for better controlling spectral boundary input in D3D wave?

In my MDW I currently set (for example):

Name = Bound1
Definition = grid-coordinates
StartCoordM = 0
EndCoordM = 0
StartCoordN = 0
EndCoordN = 29
SpectrumSpec = from file
Spectrum = point1.sp2

Which, in the INPUT file, leads to the syntax below.

BOUN SEGM IJ 0 0 0 29 &
CON FILE 'point1.sp2' 1

However, I am not using paremetric input, but 2D spectra and would like to apply it using SWAN's BOUNDSPEC command, in the following syntax.

BOUND SEGM IJ 0 0 0 29 &
VAR FILE 0 'point1.sp2'

Any ideas of how to achieve this through the MDW?

Adri Mourits, modified 4 Years ago.

RE: Boundary Flags (Answer)

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

Something like this should do:
   Name                 = Bound1                  
   Definition           = grid-coordinates            
   StartCoordM          = 2                           
   EndCoordM            = 2                           
   StartCoordN          = 2                           
   EndCoordN            = 29                           
   SpectrumSpec         = from file                   
   CondSpecAtDist       =  0.0000000e+000             
   Spectrum             = point1.sp1