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

How to calculate cum. sediment volume in a cross section or an area

JA
Jakia Akter, modified 4 Years ago.

How to calculate cum. sediment volume in a cross section or an area

Youngling Posts: 10 Join Date: 4/6/14 Recent Posts
Hi,
I have got some delft3d results files. In my domain, I have three tidal channel. I want to know how much sediment is exchanging in each channels in every year (volume vs year). I also need to know sediment exchange in some specific area. I am expecting your help. I think I have to do it in MATLAB.
Kind regards

Jakia
Adri Mourits, modified 4 Years ago.

RE: How to calculate cum. sediment volume in a cross section or an area (Answer)

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

When you add cross-sections to your model, then both the instantaneous and cumulative transports (bed and suspended) through the cross-sections are written to the his-file, for each sediment fraction.

Regards,

Adri
JA
Jakia Akter, modified 3 Years ago.

RE: How to calculate cum. sediment volume in a cross section or an area

Youngling Posts: 10 Join Date: 4/6/14 Recent Posts
Hi Adri,
Thanks for your reply.
I am facing some additional problem while calculating the sediment load/year from both *.trih (Instantaneous suspended and bed load transport through section) and *.trim (bed level differences) files. I am missing something emoticon. The results differ with 10^7 order. Would you please tell me how to include MorFac and porosity with the result files? I am usiing sand (25 m) and mud (25 m) layers. By the way, I made 240 days hydrodynamic days from 20 years data sets, that means 1 day represent a 1-month average. So, for getting 80 years morphological changes I used MorFac of 120. I want to get yearly sediment load from both the result files and to compare. For analyzing *.trim file, I deducted the floodplain sedimentation from the total polygon.
Please help me. I am not sure if I could make my queries clear enough for you.
Any type of help will be much appreciated.
Thanks and best regards
Jakia
Qinghua Ye, modified 3 Years ago.

RE: How to calculate cum. sediment volume in a cross section or an area

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

Interesting! It is quite tricky to do the mass control from the model results, in my opinion.

How big is the area approximately? The difference of 10^7 in what unit (cubic meter or kg)? did you count the part of sediment stirring to the water column, since if you start from a '0-state', no sediment will be in the water. In the first period of simulation, the system will try to get equilibrium first, then start to transport. Other than that, there is also numerical margins we kept in the system. For example, by default settings, when the sediment thickness is less than 10cm, the grid is regarded empty of sediment for erosion. I give a simple calculation here: if a cell with 100m*100m, before the simulation, it is dry. Firstly sedimentation happening, till the thickness got 10cm, it holds 10000*0.1*2650 kg of sand = 2650 ton ~ 10^6 kg. This amount can stay in the system for good.

I hope this will be a little bit helpful.

Greetings,

Qinghua