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

RE: MPI - Running parallel on windows with Delft3D 4.01.00.rc.09

KK
karunakar kintada, modified 6 Years ago.

MPI - Running parallel on windows with Delft3D 4.01.00.rc.09

Padawan Posts: 35 Join Date: 7/31/12 Recent Posts
Dear all,
Has anyone tried running the delft flow executable in parallel with the new version of delft3d.
if show please provide me the script. It was much easier earlier with mpich2 on windows xp.

Thanks in advance
Adri Mourits, modified 6 Years ago.

RE: MPI - Running parallel on windows with Delft3D 4.01.00.rc.09

Yoda Posts: 1224 Join Date: 1/3/11 Recent Posts
Hi Karunakar,

Tagged versions are fully tested, including parallel runs. Please use the latest tagged version, currently https://svn.oss.deltares.nl/repos/delft3d/tags/3574/

Example scripts are in the example directories, for example https://svn.oss.deltares.nl/repos/delft3d/tags/3574/examples/01_standard/run_flow2d3d_parallel.bat

Please read the instructions in the comments inside the script carefully.

Regards,

Adri
AE
Ahmed Elkut, modified 4 Years ago.

RE: MPI - Running parallel on windows with Delft3D 4.01.00.rc.09

Youngling Posts: 9 Join Date: 5/20/14 Recent Posts
Dear. Adri

I am using Delft3D on a workstation with Dual Intel Xeon E5 3.1 GHz processors with 10 cores for each processor, which means that i have 20 physical processors (40 logical).

I am trying to run Delft3D on windows in parallel mode. I manage to make it run, however, when i try to increase the number of cores to more than 4, i get a much longer time for calculation. I am using the configuration and batch files in the standard example for running on windows 7.

So, what i am doing wrong?, should i upgrade to windows 10? or Using Linux will be more efficient?

Best regards,
Ahmed Elkut
Adri Mourits, modified 4 Years ago.

RE: MPI - Running parallel on windows with Delft3D 4.01.00.rc.09

Yoda Posts: 1224 Join Date: 1/3/11 Recent Posts
Hi Ahmed Elkut,

The optimum number of partitions depends on a lot of factors, see the FAQ.
But 4 is indeed very disappointing. There seems to be a bottle neck, hampering a better performance. The best thing to do is to try to find out what the bottle neck is. The "tri-diag"-files (each partition produces one) might help you: timer information is added at the end of a succeeded calculation. Ideally, most of the computation time is spent on solving the equations. A high value at "Wait (ext. modules)" normally indicates that the partition is waiting for mpich to distribute data from other partitions. A high value at "postprocessing" normally inidicates that disk IO is not optimal.

If this information doesn't help, you can finish a run with for example 8 partitions, zip the tri-diag files and attach it to a post here on the forum.

Regards,

Adri
AE
Ahmed Elkut, modified 4 Years ago.

RE: MPI - Running parallel on windows with Delft3D 4.01.00.rc.09

Youngling Posts: 9 Join Date: 5/20/14 Recent Posts
Dear Adri

Thank you for your quick response. The information you have sent me is very useful. My model is relatively small and 2D, so i am expecting it to have small ONP, however, the grid is relatively fine (15*20 m on average) and i am switching on sediment transport and morphology modules, so i should expect (at least) more number of partitions that 4.
I will finish a run and check the diagnostic files. If i do not figure it out, i will send you them to you.

Note: I could not run in parallel with online coupling with wave. Should I be using the same batch file with the same configuration, or there are some other settings to set?

Best regards,

Ahmed Elkut
Adri Mourits, modified 4 Years ago.

RE: MPI - Running parallel on windows with Delft3D 4.01.00.rc.09

Yoda Posts: 1224 Join Date: 1/3/11 Recent Posts
Hi Ahmed,

Running FLOW in parallel online with WAVE is possible. An example script is in directory "...\examples\03_flow-wave".

A few remarks:
- FLOW runs parallel using MPI and can be distributed over multiple machines, as long as all machines write to the same working directory
- SWAN runs in parallel using OpenMP by default and can use all the cores on one machine. It is possible to use the MPI version of SWAN, but then you need to change some scripts. I'm sorry I don't have these changes available right now.

Regards,

Adri
AE
Ahmed Elkut, modified 4 Years ago.

RE: MPI - Running parallel on windows with Delft3D 4.01.00.rc.09

Youngling Posts: 9 Join Date: 5/20/14 Recent Posts
Dear Adri

Thank you for your help. I have already found the example script and i am modifying it now to suit my case.
I am running on one machine only for now, however, i will consider running on several machines simultaneously in the near future.

Best regards,

Ahmed