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 temperature file

Magda Sousa, modified 6 Years ago.

Space varying temperature file

Youngling Posts: 4 Join Date: 1/9/14 Recent Posts
Hi Delft3D community,

I am having some problems with the space varying temperature file in FLOW module.
I have prepared a space varying temperature file for my project (part of which is shown below):

FileVersion = 1.03
Filetype = meteo_on_equidistant_grid
n_cols = 3
n_rows = 4
grid_unit = degree
x_llcenter = -9
dx = 1.5
y_llcenter = 57
dy = -1.5
NODATA_value = 999.999
n_quantity = 1
quantity1 = air_temperature
unit1 = Celsius
TIME = 0.0 hours since 2013-09-01 00:00:00 +00:00
10.255 12.162 13.800
12.161 12.614 12.984
12.931 12.974 11.971
12.995 13.184 12.951

and I am including these files in the mdf file as specified in the FLOW manual:

Commnt =
Wnsvwp = #Y#
Wndint = #Y#
Commnt =
Commnt =
Filwu = #ERA_Interim_092013_072014.amu#
Filwv = #ERA_Interim_092013_072014.amv#
Filwp = #ERA_Interim_092013_072014.amp#
Filwt = #ERA_Interim_092013_072014.amt#
Commnt =

However, the model doesn't run and I got the following error:

*** MESSAGE Air temperature specified on a separate equidistant grid
*** ERROR Air temperature is not used in heat model (ktemp) = 0

Can anybody please help me with this or point to some possible errors I may be making?
Adri Mourits, modified 5 Years ago.

RE: Space varying temperature file

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

Air temperature is only used in two heat flux models, while you switched off the modelling of temperature completely. To switch it on in the GUI:
- Enable Temperature on the Processes tab
- On the Numerical parameters tab, Heat flux model, select a heat flux model, most commonly the "Ocean" model.

Check the manual on modelling heat transfer.