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

Ztbml bug?

SA
Steven Ayres, modified 5 Years ago.

Ztbml bug?

Padawan Posts: 33 Join Date: 4/21/11 Recent Posts
When I try to turn on the Ztbml special feature as explained in Appendix section B.26, the simulation becomes unstable and crashes after going about 10% of a 1-week simulation. I am running a Z-model parallel simulation with salinity, temperature, and fine sediment using revison #4310.

The simulation otherwise successfully completes if the feature is not used.

Has anyone else had problems using this feature?

Thanks,
Steve
Qinghua Ye, modified 5 Years ago.

RE: Ztbml bug?

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

Thank you for reporting this. In most of the cases, the Ztbml case should smooth out the aritificial velocity gradient between the cells, which should make the simulation more stable. Would you like to share the case with us, and let us have a check?

Greetings,

Qinghua
SA
Steven Ayres, modified 5 Years ago.

RE: Ztbml bug?

Padawan Posts: 33 Join Date: 4/21/11 Recent Posts
I uploaded the model files to the deltares ftp server on November 6. The zip file is under the 'Steve Ayres' directory, I just checked, it looks like it is still there.

If you add the Ztbml flag to the mdf file, you should be able to duplicate the problem.
SA
Steven Ayres, modified 5 Years ago.

RE: Ztbml bug?

Padawan Posts: 33 Join Date: 4/21/11 Recent Posts
I was able to get a run with ZTBML turned on when I turned off sediment transport. However, when I tried to restart using the map file from the ZTBML run, I got this error message "Restarting with modified layering (ZTBML=#Y#) only allowed from MAP-files with correct layer model". When I tried to get a run by turning off ZTBML on the hot-start run, I got this error message "Restarting from Z-model run with modified bed-layering only allowed with again modified layering: ZTBML=#Y#". Is there a way to create a modified MAP file to allow hot-starting with ZTBML?
Adri Mourits, modified 5 Years ago.

RE: Ztbml bug?

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

These problems might appear when restarting using a map-file created with another Delft3D-FLOW version then used for the current run. When comparing the "restart map-file creation"-run with the "current"-run, the following items must be identical:
- The Delft3D-FLOW version used
- The value of ztbml
- The layer model (sigma or Z)

If you have a testcase following these rules and you still have this problem: can you zip the files and attach that to a post on this forum?

Thanks.

Regards,

Adri
SA
Steven Ayres, modified 5 Years ago.

RE: Ztbml bug?

Padawan Posts: 33 Join Date: 4/21/11 Recent Posts
Hi Adri,

I was able to reproduce the error using the example Case 1 files. The restart worked on a serial PC run. However, when I tried a 2 core parallel linux version, the error appeared in the 2nd tri-diag file of the re-started run. So it appears to be a parallel issue. I attached the linux parallel version files for your information.

Thanks,
Steve
Adri Mourits, modified 5 Years ago.

RE: Ztbml bug?

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

Looks like a bug. Thanks for reporting this. We will look into this.

Regards,

Adri
SA
Steven Ayres, modified 4 Years ago.

RE: Ztbml bug?

Padawan Posts: 33 Join Date: 4/21/11 Recent Posts
Was this bug ever investigated? I still get this error with build #6075:

"*** ERROR Restarting with modified layering (ZTBML=#Y#) only allowed from MAP-files with correct layer model"

I am running a 216 core, 14-level Z-model with a uniform bed in Linux, the error is reported in the last tri-diag file. The error occurs when I try to re-start from a map file. I am running 2 cohesive sediment classes along with salinity and temperature. Bed level updating is inactivated.

Thanks,
Steve
Adri Mourits, modified 4 Years ago.

RE: Ztbml bug?

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

I'm sorry, it's still on my TODO list.

You have two options:
1. Solve it yourself
2. Buy a service package and then ask me to solve it

Regards,

Adri