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 create initial conditions for dam break

SS
Shawn Sim, modified 5 Years ago.

How to create initial conditions for dam break

Youngling Posts: 12 Join Date: 4/29/13 Recent Posts
Hi all,

I am doing some physical experiments with dam break propagation and would like to use Delft-3D to validate my results,
In my experiment I have a reservoir of water with dimensions as follows; in the x-dir: 7m, water depth in the reservoir is 0.5m. The other side of the reservoir is dry.
The gate mechanism of the reservoir is released at a speed of around 0.3m/s.

My question is how do I construct the initial conditions for this reservoir and its release? Do I
1) just state initial water depth as 0.5m?
2) use dry points? If so, how do I go about doing it and
3) use thin dams?

Hope I receive some help here.
Thanks!

Shawn
Adri Mourits, modified 5 Years ago.

RE: How to create initial conditions for dam break

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

Attached are (zipped in one file) the input files of two testcases:
1. dambreak wet
2. dambreak dry
These testcases are used to validate Delft3D-FLOW.

These testcases don't have a mechanism for the actual breaking of a dam; the model starts at the moment the dam is removed instantaneously. If you want to include the breaking of the dam itself, you will need to run Delft3D-FLOW online with RTC.

Regards,

Adri
SS
Shawn Sim, modified 5 Years ago.

RE: How to create initial conditions for dam break

Youngling Posts: 12 Join Date: 4/29/13 Recent Posts
Thanks Adri,

I have went through the zip file and gone through the test cases. However, I have another query.
Say my bed profile is more complex, something as shown in the attachment.
Now I want my reservoir to be at a height of 0.5m from x=0 to x=4.5 and the rest of the part dry.
How do I go about doing it?

Previously I used to create a sample file .xyz and added it into a rectangular grid in QUICKIN. However, I realised that the the 3rd colum in the .xyz file actually indicates the water depth and not the bottom profile. i.e. after x=7 in the figure, the value in the 3rd column of the .xyz file reflects water depth when I actually want it dry.

Any idea how to get around this?

Shawn
Adri Mourits, modified 5 Years ago.

RE: How to create initial conditions for dam break

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

Use the correct bathymetry (from left to right with height 0.5, 0.0 and then increasing to 5.0) and construct manually an (ASCII) inifile to define the initial water level (with from left to right values of 5.0 (your basin), and then 0.0). It will take some time to create it.

Be careful with what you want to do (/model) with Delft3D-FLOW. You might need to switch on non-hydrostatic and need a (very?) small time step.

Regards,

Adri