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. 




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



Message Boards

Flow & Wave run COM file coupling error

Clinton Chrystal, modified 7 Years ago.

Flow & Wave run COM file coupling error

Youngling Posts: 7 Join Date: 11/26/12 Recent Posts
Hi everyone, trust you well.
I hope this is just a newbie error that is simple to sort out.

I have successfully run some Delwaq simulations, and the process seems fine when I generate the COM file in the flow output, with flow as a driven only.
But as soon as I run Flow & Waves, my COM file start and stop times are equal, with a zero time step, thus giving me nothing to couple for Delwaq.
If i switch off the waves, then the COM file is fine, with the start and stop time matching the simulation period, and the time step as specified.

Is this a general problem? I would appreciate any assistance in the regard.
Many thanks in advance.
Kind regards,
Arjen Luijendijk, modified 7 Years ago.

RE: Flow & Wave run COM file coupling error

Padawan Posts: 38 Join Date: 2/22/11 Recent Posts
Hi Clint,
Good to hear from you!
I'm not sure that i fully understand your question, but in the FLOW GUI you can prescribe the start and stop time for the com-file even when you have activated the coupling with WAQ (by activating the 'Online coupling' under Output. So simply adjust the times manually. Let us know whether this works or when your problem is more complex.

Cheers, Arjen
Clinton Chrystal, modified 7 Years ago.

RE: Flow & Wave run COM file coupling error (Answer)

Youngling Posts: 7 Join Date: 11/26/12 Recent Posts
Hi Arjen,
man I'd give you a hug if we were in the same room. emoticon

Turns our your suggestion was spot on. Not sure why the post-run coupling was not working with the Waves included,
but I ran a small test case with FLow and Waves, and the online coupling files was produced with the correct time periods for DelWaq to load.
I've started a longer simulation, but it appears to be working.

Thanks so much for the speedy repsonce.
Have a great day!
Cheers, Clint
Amelia Araujo, modified 3 Years ago.

RE: Flow & Wave run COM file coupling error

Youngling Posts: 13 Join Date: 7/7/15 Recent Posts
Hi Arjen,

I am using the waves for the first time in my hydrodynamic model together with tides, and got exactly the same issues as Clint when trying to do the coupling for Delwaq. In your reply you suggest to use "online coupling". Where can I find that field? In the .mdf file, Outputs, I can only see "online visualisation". Do you mean that? It does not make sense to me.


Michel Jeuken, modified 3 Years ago.

RE: Flow & Wave run COM file coupling error

Jedi Knight Posts: 154 Join Date: 1/21/13 Recent Posts

It used to be called 'online coupling', but that was confusing, since water quality it self isn't coupled online, and the direct writing of WAQ input is not 'online', but fully integrated in the code of FLOW. So in newer versions of the FLOW user interface, on the last Output tab is is called Export WAQ Output.