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

Time-varying BC in Delft3D-Waves: wavecon vs *.BCW

Ruairi MacIver, modified 6 Years ago.

Time-varying BC in Delft3D-Waves: wavecon vs *.BCW

Padawan Posts: 45 Join Date: 5/1/13 Recent Posts
I'm running a standalone WAVE model on a rectangular grid with domain boundaries as essentially: 1) the shoreline; 2) the offshore boundary (roughly shore parallel); 3) side boundaries are roughly perpendicular to the shoreline. I wish to specify time-varying (half-hourly) boundary conditions on the offshore boundary and at this stage am happy to apply a uniform condition.

Two approaches are apparent from the Delft3D-WAVE manual: the use of a wavecon.rid file (A.2.8.1) and the use of a .BCW file (A2.8.2).

Question: What is the distinction between the two approaches? The .BCW file appears to be the more versatile approach.

The manual indicates certain consequences of using the wavecon approach (e.g. the period value is assumed to be a peak period by default) and previous posts have suggested that the BCs in the wavecon file are applied to ALL domain boundaries. I have also observed the following runtime warning "Warning: ... degrees modified to power" which I presume refers to the directional spread parameter which is specified as provided in degrees in the *.mdw file and in the wavecon file.

Question: If the power representation of the directional spread is used, is the degree data provided in the wavecon converted to the equivalent power data?

Any thoughts on the above?

Ruairi
Qinghua Ye, modified 6 Years ago.

RE: Time-varying BC in Delft3D-Waves: wavecon vs *.BCW (Answer)

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

Question: What is the distinction between the two approaches? The .BCW file appears to be the more versatile approach.

My answer: Yes. BCW file approach is a newer approach in Delft3D-WAVE.

Question: If the power representation of the directional spread is used, is the degree data provided in the wavecon converted to the equivalent power data?

My answer: Yes. It is converted to the power data.


Regards,

Qinghua
mohammad rahmanian, modified 6 Years ago.

RE: Time-varying BC in Delft3D-Waves: wavecon vs *.BCW

Youngling Posts: 6 Join Date: 5/27/12 Recent Posts
Hello Dear.Qinghua Ye

Special thank you ,Therefore According to your description the only way to simulate time varying wave parameters with space varying boundary conditions is Using BCW file. I would be appreciated if you tel me , which versions of Delft3D can support BCW file.

Best Regards

Mohammad
Qinghua Ye, modified 6 Years ago.

RE: Time-varying BC in Delft3D-Waves: wavecon vs *.BCW

Jedi Council Member Posts: 612 Join Date: 3/2/11 Recent Posts
dear Mohammad,

The feature of BCW is included in 2012. I am sure in all the versions from 2013, you can use the BCW files.

Otherwise let me know.

Regards,

Qinghua
FK
Fajar Khaedir, modified 5 Years ago.

RE: Time-varying BC in Delft3D-Waves: wavecon vs *.BCW

Youngling Posts: 8 Join Date: 4/7/14 Recent Posts
Hi Qinghua,

Can you explain me more about "choice for degrees modified into power"?
If I understand well your answer, then the directional spreading input (in degree) on wavecon file will be converted to cosine power. But why is this happen? I did changed the directional spreading on spectral space to degrees (standard deviation).
However, the result shows different directional spreading between the one I put on the wavecon file with the directional spreading on the wavm file.
I attach csv file from wavm to make my question clear, including my input data. I hope you can help me to put this right. Thanks.

Regards,
Fajar
Ruairi MacIver, modified 5 Years ago.

RE: Time-varying BC in Delft3D-Waves: wavecon vs *.BCW (Answer)

Padawan Posts: 45 Join Date: 5/1/13 Recent Posts
Hi Fajar,

Certainly in the supported release 3.04.01.757of Delft3D, and in the open source tagged release 3426, the directional spreading values in a wavecon file are simply interpreted as an ‘s’ value regardless of what is selected in the GUI [or specified in the boundary section of the MDW file]. There was no conversion from one representation to the other.

This may have been modified in later releases, however I haven't used the wavecon approach recently so can't comment.

Regards
Ruairi
Kyssyanne Oliveira, modified 2 Years ago.

RE: Time-varying BC in Delft3D-Waves: wavecon vs *.BCW

Youngling Posts: 13 Join Date: 9/4/13 Recent Posts
Hello Dear.Qinghua Ye
In wavecon we use "Mean wave direction", in TPAR file we use "Peak direction". The manual is not clear what direction we should use in .bcw file: peak or mean wave direction. I have the same doubt about the directional spread.
Thanks,
Kyssyanne
Qinghua Ye, modified 2 Years ago.

RE: Time-varying BC in Delft3D-Waves: wavecon vs *.BCW

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

If I remember correctly, the direction in BCW is the same as the definition of wavecon, i.e. mean wave direction. But I need more time to confirm it. After confirm it, I would update the Wave Manual as well.

Direction spreading is not relavant with this.

Greetings,

Qinghua