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

Boundary conditions

FM
florian MONETTI, modified 7 Years ago.

Boundary conditions

Youngling Posts: 21 Join Date: 3/12/13 Recent Posts
Hi,

I work with ROMS model and I would like to run localy a Delft3d simulation with waves and flows (sediment transport included) from ROMS ouputs (Nesting offline).
I have current components and sea level.

If I understand, I could only implement the current components at the boundaries with Time series files, isn't it?

Anyone tryed to work with Delft3d from Roms? Is there any program to generate delft3d current conditions from 3d netcdf file?

Thanks.

Florian
Physical oceanographer
Renan Ribeiro, modified 7 Years ago.

RE: Boundary conditions

Padawan Posts: 55 Join Date: 3/23/11 Recent Posts
Hi Florian,

1º question: You can specify harmonic components at the boundary, even as current. However, if you have a variation of mesoscale signal I think that time series is better. A way to force the model with currents and elevation is to use a boundary condition called Riemann.

2º question: Yes. There are some matlab scripts from OpenEarthTools to convert netcdf files to .mat and after generate the boundary conditions file (.bct). Download this tools and search for nesting.

Let me know if you find.

Regards,
Renan
FM
florian MONETTI, modified 7 Years ago.

RE: Boundary conditions

Youngling Posts: 21 Join Date: 3/12/13 Recent Posts
Hi Renan,
Thanks for your answer.
I will search the mean to use the matlab opentool box to create boundaries conditions.

Have you work with output of other model for a nested simulation in Delft3d?

Regards,

Florian
FM
florian MONETTI, modified 7 Years ago.

RE: Boundary conditions

Youngling Posts: 21 Join Date: 3/12/13 Recent Posts
Renan,

NESTHD use output of an other Delft simulation, isn't it?

What I want to find or create is a matlab program to generate .bct and .bcc files from 3D netcdf files.
Open Earth toolbox has a program like that?

Regards,

Florian
Renan Ribeiro, modified 7 Years ago.

RE: Boundary conditions

Padawan Posts: 55 Join Date: 3/23/11 Recent Posts
Hi Florian,

Yes, I have worked with some simulations using outputs of the Hycom model to force Delft3D, most of these successfully.

Nesthd uses Delft3D to Delft3D. At OpenEarthTools have a matlab script (it isn't a program, you need to have matlab), you need to organize the model outputs in .mat files and a .xml with the paths of delft3d project. It has an example here. You need to run nst.m script.

Follow attached an example of .mat files with outputs of the Hycom model

Regards,
Renan
TL
Tony Lee, modified 3 Years ago.

RE: Boundary conditions

Youngling Posts: 9 Join Date: 4/1/17 Recent Posts
Excuse me, Renan,
I am puzzled with the way of converting hycom nc data to boundaries condition for D3D flow. Could you please express the way in detail?I appreciate any kind of help.
Renan Ribeiro, modified 3 Years ago.

RE: Boundary conditions

Padawan Posts: 55 Join Date: 3/23/11 Recent Posts
Dear Tony Lee,

0. First, you need to download and "install" the OpenEarthTools at your matlab

1. Convert the hycom results (water level and currents) to a matlab format (.mat files), like these ones above. There are some scripts at OpenEarthTools that can do this, here.

2. Configure your Delft3D project (.mdf file) with all the boundaries you want to use and also indicate the type of boundary, 2D, or 3D,... (I usualy use Riemann boundary type).

3. Configure this .xml file indicating the path of hycom files, .mdf files, variables (water level, currents | temperature, salinity,if so).

4. Run the nst.m script avaliable here, to generate the inicial condition file (.ini), boundary condition file (.bct, .bcc).

Best regards,
Renan
TL
Tony Lee, modified 3 Years ago.

RE: Boundary conditions

Youngling Posts: 9 Join Date: 4/1/17 Recent Posts
Thank you so much!

I am sorry it took me so long to get back to you on this. I just returned to the problem today, it seems the m file you provided is not in detail .emoticon
I will try my best to cope.

Sincerely,
Tony
SS
Suraj Singh, modified 2 Years ago.

RE: Boundary conditions

Youngling Posts: 2 Join Date: 10/6/18 Recent Posts

Dear Renan,

Thank you for all your information regarding the above queries on generating .ini, .bct, .bcc file from hycom data.

I followed your suggestions, I am able to generate.mat files from hycom data. However, I am not clear about the step 3 and 4. Could you kindly explain them in detail; nst.m script is also not clear or could you share any script to generate .ini, .bct, .bcc file?

 

Thanks,

Suraj