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

problem coupling waves and flow

Mallory Barkdull, modified 3 Years ago.

problem coupling waves and flow

Youngling Posts: 3 Join Date: 2/12/13 Recent Posts

I have a 2D (x-y) model that works great when I just have FLOW running, but when I add waves it runs for about 5% of the time and then gives me the following error:

C:\Users\mbarkdu\Dropbox\model runs\A_waves_tides_wind_2d>rem exit
>>...End of SWAN run
Allocate output fields
Read SWAN output
WARNING: Found negative value(s) for dissip(2) in swanout file;
value(s) set to zero
Map WAVE parameters to FLOW grid 1

forrtl: The process cannot access the file because it is being used by another process.

forrtl: severe (28): CLOSE error, unit 32, file "Unknown"

Image PC Routine Line Source
libifcoremd.dll 100AAD2A Unknown Unknown Unknown
libifcoremd.dll 1001D15B Unknown Unknown Unknown
libifcoremd.dll 1001C31B Unknown Unknown Unknown
libifcoremd.dll 10011418 Unknown Unknown Unknown
wave.exe 00474194 Unknown Unknown Unknown
wave.exe 00401EAE Unknown Unknown Unknown
wave.exe 004E63F3 Unknown Unknown Unknown
wave.exe 004E44AA Unknown Unknown Unknown
KERNEL32.DLL 74E97C04 Unknown Unknown Unknown
ntdll.dll 7755AB8F Unknown Unknown Unknown
ntdll.dll 7755AB5A Unknown Unknown Unknown

Does anyone know how to fix this problem?