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

error during wave alone simulation, 2 different boundary conditions (TPAR)

George Victor, modified 2 Years ago.

error during wave alone simulation, 2 different boundary conditions (TPAR)

Youngling Posts: 7 Join Date: 5/19/17 Recent Posts
Hi everyone, Recently i was doing a wave alone simulation over a bay (Palk Bay). Since the study location is dominated by sea waves, local winds (u and v components from ERA-INTERIM) are given as the inputs. The location has got 2 openings geographically- one in the south and and the other in the north-east. Boundary conditions are applied along these 2 openings. Although the whole bay domain is small, since both the openings/boundaries are facing 2 different wave habitats, different boundary conditions are to be applied. To do the same, wave boundary conditions along the north east are applied using "wavecon file, while the southern boundary condition is applied using a TPAR file. The format for both the files are checked (attached). The simulation period is one month (JUNE). However, when the run is made, the model ends up with error "norm end", just before the first iteration for the first time step. The model was successfully running with the same parameters, with the southern boundary condition (TPAR file) removed.
I had also moved all the necessary files to a new folder and tried a 2nd time, but the error still remains. (No err file is generated during the same.)

What could be done to rectify the error.


Starting Delft3D-WAVE computation ...
- Delft3D
- Deltares, Delft3D-WAVE Version, Oct 22 2014, 08:53:31
- Open source
*** MESSAGE: Delft3D-WAVE runs stand alone
SWAN_INPUT: [Processes] WaveForces is set to "dissipation 3d"
To switch on radiation stresses: "WaveForces = radiation stresses <2013"
SWAN_INPUT: Meteofiles specified in group General used for domain 1
Done reading input
Initialising grids and grid mappings
Reading conditions from wavecon file
132480.00 0.10 10.03 170.00 4.00 0.00 0.00 0.00
Start loop over SWAN grids, time = 132480.000
Allocate input fields
Allocate and read SWAN depth
Write SWAN depth file
Write SWAN wind file
Deallocate input fields
Write SWAN input
<<Run SWAN...
SWAN batchfile executed for Delft3D
Using swan.bat in directory C:\win32\swan\scripts\
Using C:\\win32\swan\bin\swan_4072ABCDE_del_w32_i11_omp.exe
Performing wave computation for: all.swn
1 file(s) copied.

SWAN is preparing computation

1 file(s) copied.

I:\ALL1-2>rem exit
>>...End of SWAN run
*** ERROR: file 'norm_end' expected to signal a correct SWAN calculation

forrtl: severe (64): input conversion error, unit -5, file Internal Formatted Read

Image PC Routine Line Source
swan_4072ABCDE_de 00582A8A Unknown Unknown Unknown
swan_4072ABCDE_de 00530BEB Unknown Unknown Unknown
swan_4072ABCDE_de 0052FDAB Unknown Unknown Unknown
swan_4072ABCDE_de 0051541F Unknown Unknown Unknown
swan_4072ABCDE_de 0051374C Unknown Unknown Unknown
swan_4072ABCDE_de 0043419E _RBFILE 5626 swanmain.for
swan_4072ABCDE_de 0043085D _SNEXTI 4838 swanmain.for
swan_4072ABCDE_de 00426CBA _SWMAIN 532 swanmain.for
swan_4072ABCDE_de 00425CAB _MAIN__ 110 swanmain.for
swan_4072ABCDE_de 00588A33 Unknown Unknown Unknown
swan_4072ABCDE_de 0056B74E Unknown Unknown Unknown
KERNEL32.DLL 745D62C4 Unknown Unknown Unknown
ntdll.dll 77900F79 Unknown Unknown Unknown
ntdll.dll 77900F44 Unknown Unknown Unknown

Joseph Morrow, modified 2 Years ago.

RE: error during wave alone simulation, 2 different boundary conditions (TP (Answer)

Youngling Posts: 5 Join Date: 11/16/16 Recent Posts
you could try delimiting your tpar file with a single space instead of tabs. Switching from tab delimited to space delimited helped me out with a similar problem.
George Victor, modified 2 Years ago.

RE: error during wave alone simulation, 2 different boundary conditions (TP

Youngling Posts: 7 Join Date: 5/19/17 Recent Posts
Thank you a lot. Your solution worked.