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

Dredging activity - Suspended Sediment

MF
Maria Fiedler, modified 8 Years ago.

Dredging activity - Suspended Sediment

Youngling Posts: 4 Join Date: 2/21/12 Recent Posts
Hello,

Delft3D simulates dredging activity but I would like to know if it simulates the suspended sediment as a consequence of the dredging activity (the suspended sediment when the dredging is happening) and how can I see it.

Thanks in advance,

Maria Fernanda Mendes Fiedler.
Fernando Barreto, modified 6 Years ago.

RE: Dredging activity - Suspended Sediment

Padawan Posts: 74 Join Date: 6/21/12 Recent Posts
Does someone Know the answer to this question?
Qinghua Ye, modified 6 Years ago.

RE: Dredging activity - Suspended Sediment

Jedi Council Member Posts: 610 Join Date: 3/2/11 Recent Posts
Hi Maria,

To simulate the suspended sediment as a consequence of the dredging activity (the suspended sediment when the dredging is happening) is a complex phenomenon and many processes are involved, such as, sediment stiring up by the cutting head, mixing by the turbulence caused by the movement of cutting head, part of the sediment settling down in the adjacent area, and the other part staying in the water column, transport by the current to further area.

If you only care about the influence area of dredging in general, for environment purpose, Delft3D can usually fulfil this purpose. If you are also interested in the sediment stiring and mixing processes, some plume-type model, like cormix, visjet, jetlag etc. should be used to provide the sediment source for Delft3D.

Deltare did a lot of experiments in the last 5-10 years and has been applied and tested in the industry. Refer to http://www.deltares.nl/en/expertise/101121/intake-and-outfall-systems/2047789. If you have more specific questions, you can always contact us directly.

Regards,

Qinghua
U
Li Haijun, modified 6 Years ago.

RE: Dredging activity - Suspended Sediment

Hello Qinghua,
Dredging activities may have great effects on the suspended sediment concentration.
I want to know the change of suspended sediment concentration after dredging activities. Delft3D can simulate dredging activities. How can I see the result of suspended sediment changes resulting from dredging? Should I install the CORMIX combined with Delft3D(Refer to http://www.deltares.nl/en/expertise/101121/intake-and-outfall-systems/2047789) or using Delft3D only?
I did two test simulation with one dredging and another not. But it seems that there was no differences in the two conditions. Dredging activities showed no impact on the suspended sediment concentration. Can you give me some advices?


Thanks
Li Haijun
Qinghua Ye, modified 6 Years ago.

RE: Dredging activity - Suspended Sediment

Jedi Council Member Posts: 610 Join Date: 3/2/11 Recent Posts
dear Li Haijun,

How did you include the dreding activity in the Delft3D, without including Cormix? Can you give a bit more information?

Regards,

Qinghua
U
Li Haijun, modified 6 Years ago.

RE: Dredging activity - Suspended Sediment

Dear Qinghua,

Thank you for your reply.I did those two test simulations without including Cormix.

In the "Flow Input", the man-made process "Dredging and dumping" was switched on and the tab "Dredging and dumping" in the "Operations" domain was available.

Following the FLOW-User-Manual, I used a keyword "Fildad" in the "Additional parameters" domain with the value "#dredgingTest.dad#". The dredging areas was defined in the

".dad" file using QUICKIN by defining the dredging polygon and its depth.


The manual describes that it will simulate as sand mining by defining the dumping area out of the grid. But I see no different impacts on the Suspended Sediment

Concentration between those two conditions.

Did I get something wrong? Can I simulate the effects of dredging activities on sediment concentration using Delft3D individually?


Sincerely,

Li Haijun
Qinghua Ye, modified 6 Years ago.

RE: Dredging activity - Suspended Sediment

Jedi Council Member Posts: 610 Join Date: 3/2/11 Recent Posts
Dear Li Haijun,

As I understand, the "Dredging and dumping" is only used as a mass changing of sediment, which is, moving the dredging volume of sediment directly to the dumping area, without releasing to the water column. It is of course not nature and not include the dredging plume etc processes. Thus you will definitely not see any change of sediment concentration.

This operation is not design for that. You have to include the near field processes if you want to see the effects of dredging activities on sediment concentration.

Greetings,

Qinghua
U
Li Haijun, modified 6 Years ago.

RE: Dredging activity - Suspended Sediment

Dear Qinghua,

Thank you for your reply.

It seems that the dredging and dumping was designed mainly to study the impact on the long-term morphological evolution. I was advised to do the simulation by adding discharge points to represent the source of suspended sediment caused by dredging activities.

I will do another more test to find if that works or not.

By the way, what kind of near field process should I include? Field observations of suspended sediment concentration near the dredging area?


Li Haijun
Qinghua Ye, modified 6 Years ago.

RE: Dredging activity - Suspended Sediment

Jedi Council Member Posts: 610 Join Date: 3/2/11 Recent Posts
Dear Li Haijun,

Sure using operational points will change the suspended sediment transport field.

You can check http://www.cormix.info/methodology.php for the near field processes.

Enjoy,

Qinghua
JF
João Paulo Ferreira, modified 4 Years ago.

RE: Dredging activity - Suspended Sediment

Padawan Posts: 32 Join Date: 10/16/15 Recent Posts
Hello everybody.

I would try to run a time series of dredging and dumping.
As I call DDT file in the MDF?
It would be a command like "Filddt"?

Thank you!
Adri Mourits, modified 4 Years ago.

RE: Dredging activity - Suspended Sediment

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

Attached is a complete set of input files for a simulation with a dredge/dump time serie. I'm sorry that it is more complex than you need, for example DomainDecomposition is used.

Regards,

Adri
JF
João Paulo Ferreira, modified 4 Years ago.

RE: Dredging activity - Suspended Sediment

Padawan Posts: 32 Join Date: 10/16/15 Recent Posts
Thanks very much Mourits!!!