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

Space varying wind and atmospheric pressure file

Rohit Kulkarni, modified 6 Years ago.

Space varying wind and atmospheric pressure file

Youngling Posts: 8 Join Date: 8/16/12 Recent Posts
Hi Delft3D community,

I am having some problems with the space varying wind and pressure files in FLOW module.
I have prepared a space varying wind and atmospheric pressure file for my project (part of which is shown belowemoticon
FileVersion      = 1.03
Filetype         = meteo_on_equidistant_grid
n_cols           = 7
n_rows           = 6
grid_unit        = degree
x_llcenter       = 301.5
dx               = 0.75
y_llcenter       = -33.75
dy               = -0.75
NODATA_value     = 999.999
n_quantity       = 1
quantity1        = x_wind
unit1            = m s-1

^ Is the order of the keywords important?
TIME =     0 minutes since 2004-01-01 00:00:00 -03:00
-1.3201    -1.4815   -1.5263   -1.2902   -0.9658   -0.4369    0.1374
-0.9451    -1.5998   -1.5745   -1.2506   -0.6298    0.4934    2.3730
-0.8222    -0.8658   -1.4229   -0.9618   -0.0182    1.1590    2.4569
-0.8090    -0.8205   -0.7814   -0.3507    0.4309    1.4054    2.5775
-0.7941    -0.6752   -0.2439    0.4705    0.9672    1.7281    2.7733
-0.4541    -0.0711    0.9351    1.1315    1.3617    1.8964    2.8359
TIME =    360 minutes since 2004-01-01 00:00:00 -03:00

and I am including these files in the mdf file as specified in the FLOW manual:
Commnt =                  
Wnsvwp = #Y#
Wndint = #Y#
Commnt =               
Commnt =                  
filewu = #test.amu#
filewv = #test.amv#
filewp = #test.amp#
Commnt =                  

I tried a simulation with this, but there appears to be no effect of the wind on the model (I ran for a period of a month, just to be sure). The simulation runs though, and doesn't show any error.
Can anybody please help me with this or point to some possible errors I may be making?
Adri Mourits, modified 6 Years ago.

RE: Space varying wind and atmospheric pressure file

Yoda Posts: 1224 Join Date: 1/3/11 Recent Posts
Hi Rohit,

The crucial point is the lines numbered 9, 10, 11 in your mdf-file snippet; the keywords "filewu/v/p" must be written without the character "e":
filwu = #test.amu#
filwv = #test.amv#
filwp = #test.amp#

I checked the manual and it seems alright in there. If you have some documentation using the wrongly "filewu", please let me know so that we can correct that.

Additional remarks:
  • No, the order of the keywords in the header of the meteo-file is not important.
  • The lines "Wnsvwp = #Y#" and "Wndint = #Y#" are not needed.
  • When adding the line "Airout= #Y#" to the mdf-file, the air related parameters will be written to the output files (interpolated to the calculation grid). In this way, you can check the wind being used.


Rohit Kulkarni, modified 6 Years ago.

RE: Space varying wind and atmospheric pressure file

Youngling Posts: 8 Join Date: 8/16/12 Recent Posts
Thank you so much! emoticon