intro story Coast / Estuary

Coast / Estuary

Coastal systems are among the most dynamic physical systems on earth and are subject to a large variety of forces. The morphodynamic changes occurring to coastlines worldwide are of great interest and importance. These changes occur as a result of the erosion of sediments, its subsequent transport as bed load or suspended load, and eventual deposition. 
 
Estuaries are partly enclosed water bodies that have an open connection to the coast. Estuaries generally have one or more branching channels, intertidal mudflats and/or salt marshes. Intertidal areas are of high ecological importance and trap sediments (sands, silts, clays and organic matter).
Within the Delft3D modelling package a large variation of coastal and estuarine physical and chemical processes can be simulated. These include waves, tidal propagation, wind- or wave-induced water level setup, flow induced by salinity or temperature gradients, sand and mud transport, water quality and changing bathymetry (morphology). Delft3D can also be used operationally e.g. storm, surge and algal bloom forecasting. 
 
On this discussion page you can post questions, research discussions or just share your experience about modelling coastal and/or estuarine systems with Delft3D FM. 
 

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Sub groups
D-Flow Flexible Mesh
DELWAQ
Cohesive sediments & muddy systems

 

 

Message Boards

MPI - Running parallel on windows

LH
Li Haijun, modified 5 Years ago.

MPI - Running parallel on windows

Youngling Posts: 15 Join Date: 7/4/14 Recent Posts
Dear all,
Has anyone tried running the delft flow executable in parallel using MPI mpich2 on windows?
I have run the example provided on a computer server with 12 CPUs and 24 cores and it worked well. But when I run my own flow(3d) model, it does not speed-up so much.
Does anybody know why?How many CPUs and cores should I use in order to achieve the optimal computation?Should I rebuild and recompile the open source to get the MPI running version of Delft3D?

Thanks in advance
Li Haijun
AM
Arjen Markus, modified 5 Years ago.

RE: MPI - Running parallel on windows

Jedi Knight Posts: 223 Join Date: 1/26/11 Recent Posts
Li Haijun, you sent this to the part of the forum that is devoted to water quality modelling. I think you meant to send it to the FLOW part instead.

Delft3D-WAQ does have some multiprocessing features, but they are most useful in the context of evaluating the processes in parallel and for that we do not use MPI but OpenMP.
LH
Li Haijun, modified 5 Years ago.

RE: MPI - Running parallel on windows

Youngling Posts: 15 Join Date: 7/4/14 Recent Posts
Hi Arjen,

Thank you for your reply.

I may send a new post to the FLOW part. Exactly I run a FLOW model instead of WAQ.

Regards,

Li Haijun
Adri Mourits, modified 5 Years ago.

RE: MPI - Running parallel on windows (Answer)

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

Please have a look at the FAQ.

Regards,

Adri
LH
Li Haijun, modified 5 Years ago.

RE: MPI - Running parallel on windows

Youngling Posts: 15 Join Date: 7/4/14 Recent Posts
Hi Adri,

My model has a mmax of 186 and a nmax of 482. Does it mean that the number of partitions(ONP) should be lower?
I run the model in MPI parallel using 2 CPUs and 2 cores for fastest computation. However, the time it costs nearly the same as computation without MPI. Sometimes it even slower. Maybe it's better to just run it without MPI parallel.

By the way, should I compile the source again with MPI environment in the Visual Studio 2010 to run a right MPI parallel computation of FLOW?

Thank you,

Li Haijun