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! 

 

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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: 
/web/delft3dfm/forum

Post your questions, issues, suggestions, difficulties related to our Delft3D Flexible Mesh Suite on the new forum.

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** PLEASE TAG YOUR POST! **

 

 

Sub groups
D-Flow Flexible Mesh
DELWAQ
Cohesive sediments & muddy systems

 


Message Boards

The difference between them was the vertical coordinate, one sigma and the

LS
LUIS HENRIQUE SILVA, modified 7 Years ago.

The difference between them was the vertical coordinate, one sigma and the

Youngling Posts: 12 Join Date: 9/30/11 Recent Posts
Dear Adri,
I carried out two experiments, both forced by tide (amplitude and phase)
prescribed at a file *.bca. Both with 1 layer, size 92X91, barotropic. The
difference between them was the vertical coordinate, one sigma and the
other Z.

I think the results should be the same, but they are different: the run with
sigma coordinate was noisy ... Please, have a look in the figures, where the
water level is shown after an integration of 15 days.

Do you know what is happening ?

regards

Luis
Adri Mourits, modified 7 Years ago.

RE: The difference between them was the vertical coordinate, one sigma and

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

That looks very weird indeed.

Although both calculations are with one layer, the actual algorithms are really different. The Z-layer algorithm is more explicit.If you use the same timestep for both simulations, I expect the sigma-model to produce better results, which does not seem to be the case.

What happens if you reduce the time step?

If you scan the output between t=0 and t= 15 days, is there a point in time and/or space where it starts to become ugly?

Regards,

Adri