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

online delft3d flow and swan coupling

HE
hoda el safty, modified 4 Years ago.

online delft3d flow and swan coupling

Youngling Posts: 12 Join Date: 6/19/13 Recent Posts
Dear all,

I am trying to run flow3d flow and swan in two way coupling/online coupling but I am getting very small wave setup and very small wave-induced current.
Any hints to why is this happening.

Best,
hoda
Adri Mourits, modified 4 Years ago.

RE: online delft3d flow and swan coupling (Answer)

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

Can you give some more information about your model? Ideally, can you zip your input files and attach it to a post here on this forum?

Thanks.

Adri
Adri Mourits, modified 4 Years ago.

RE: online delft3d flow and swan coupling

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

Your model looks decent. A computed wave height of about 1m should be enough to generate some effects.

What happens if you switch off the roller model?

How do you messure the wave setup?

Regards,

Adri
HE
hoda el safty, modified 4 Years ago.

RE: online delft3d flow and swan coupling

Youngling Posts: 12 Join Date: 6/19/13 Recent Posts
Hi Adri,

The wave induced current is very small. In order to compute the wave setup, I add in the "Additional parameters" under "Processes" I add " WaveSetup" then "true" infront of it. But I get wave setup in order of few millimeters. And the same when I turn the roller model off

So I have few notes

1)- When the roller model is on, the wave height is computed from the roller equations not in Swan, is that correct?

I see a huge difference in the wave height when I turn the roller model on compared to the one calculated from SWAN

Thanks

hoda
Adri Mourits, modified 4 Years ago.

RE: online delft3d flow and swan coupling (Answer)

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

This WaveSetup is calculated by SWAN. That means that the actual setup as calculated by Delft3D-FLOW (using the wave data created by SWAN) will be different (FLOW does not take the SWAN-setup into account).

If you want to know the setup in your FLOW model, you will have to do a calculation with and without WAVE and look at the differences.

If you want to know why SWAN came with this setup, you will have to contact the SWAN community.

Regards,

Adri
HE
hoda el safty, modified 4 Years ago.

RE: online delft3d flow and swan coupling

Youngling Posts: 12 Join Date: 6/19/13 Recent Posts
Hi Adri

Thank for the reply. So if i want to calculate the wave setup then i will have to
1)- run flow only
2)-run flow+wave
3) subtract the water level to get the actual setup in the simulation due to waves

is that correct?

Also, I see that the radiation stresses calculated in SWAN is very small, any hints for that

Best,

hoda
Adri Mourits, modified 4 Years ago.

RE: online delft3d flow and swan coupling

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

Yes, that's correct. I don't know a shorter/direct way to get the setup.

I'm sorry, no idea.

Regards,

Adri
JM
Jos Muller, modified 2 Years ago.

RE: online delft3d flow and swan coupling

Youngling Posts: 3 Join Date: 10/7/16 Recent Posts
Hi Adri, Hi all,

I'm experiencing kind of similar problem.

I've set up a single domain FLOW model, which works fine when running it alone. Now I want to add wind-induced waves to this domain with a online simulation. I added wind information to the .mdf file and I managed to successful run the model (parallel over 4 cores), which uses but not extend the wind, waterlevel, current and bathymetry. I did not set any further boundary wave conditions.

However, during the calculation, the wave simulation only require one iteration and immediately reaches 100% accuracy and the output does not show any wave generation at all. The wind input in the output from the .mdw file is correct though. It looks like swan is not recognizing the wind input for wave generation?

Does this sounds familiar? I can provide the model set up if necessary

Thanks for your help,
Jos