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

dd "WARNING: Depth difference on couple boundary above 5.000000"

ZV
Zoe Vosberg, modified 7 Years ago.

dd "WARNING: Depth difference on couple boundary above 5.000000"

Youngling Posts: 10 Join Date: 6/11/12 Recent Posts
Hi,

I'm currently trying to refine a grid by using the domain decomposition function of the DelftDashboard.

I exactly followed all the steps explained in the webinar 'How to set up a Delft3D model with Delft Dashboard' and used the same parameters, just for a different region.

The models runs but in the end I get the warning

WARNING: Depth difference on couple boundary above 5.000000
context[ 1].DPV(208,101) = 1860.669788 , context[ 0].DPV( 3,37) = 2155.743680

Anybody knows how to solve this?

Thanks,
Zoe
Qinghua Ye, modified 7 Years ago.

RE: dd "WARNING: Depth difference on couple boundary above 5.000000"

Jedi Council Member Posts: 612 Join Date: 3/2/11 Recent Posts
Hi Zoe,

The warning is about the depth along the boundary lines. So for domain decomposition, the depth along the shared boundary lines should be identical to assure the smooth interaction between domains.

Regards,

Qinghua
ZV
Zoe Vosberg, modified 7 Years ago.

RE: dd "WARNING: Depth difference on couple boundary above 5.000000"

Youngling Posts: 10 Join Date: 6/11/12 Recent Posts
Hi Qinghua,

thanks a lot for your answer!

I'm a bit surprised about these depth differences because I created both domains with the dashboard. Shouldn't the depth along the shared boundary line automatically be identical in that case? What can I do to control and assure this next time?

Regards, Zoe
Adri Mourits, modified 7 Years ago.

RE: dd "WARNING: Depth difference on couple boundary above 5.000000" (Answer)

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

Sometimes it can not be avoided, for example when having a DD boundary in a steep area using refinement. Moving the DD boundary (to a more flat area) or reducing the refinement may help.

Regards,

Adri
ZV
Zoe Vosberg, modified 7 Years ago.

RE: dd "WARNING: Depth difference on couple boundary above 5.000000"

Youngling Posts: 10 Join Date: 6/11/12 Recent Posts
Hi Adri,

thanks for your advice! I will try to move the boundaries.

Regards, Zoe
JA
Jon Allen, modified 7 Years ago.

RE: dd "WARNING: Depth difference on couple boundary above 5.000000"

Youngling Posts: 1 Join Date: 7/17/12 Recent Posts
We have a DD FLOW-WAVE model that fails to run do to this issue. Depth differences at coupling boundaries (also generated with Dashboard) result in fatal WL gradient errors.

In our case, moving the boundaries is not an option; therefore, does any one know if I copy the boundary depth profiles of one domain to another using the GUI?

If not, is this easy to accomplish in MATLAB without upsetting the unusual free formatting that Delft3D requires of the depth file, which does not lend itself to import?

Thanks,
Jon
Adri Mourits, modified 7 Years ago.

RE: dd "WARNING: Depth difference on couple boundary above 5.000000"

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

I'm not very familiar with Quickin, but isn't it possible to import depth values from one domain as sample values in the other domain?

It is good to try this option. Please post your findings here. But it is possible that it will not solve your problem. If your depth profile itself is steep and you use refinement, you may still have the same error.

Regards,

Adri