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

 


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RE: Delft3D-FLOW "Mass closure error" warning

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Hello,

I was wondering if anyone might be help me out with what this warning means. I tried to look at the flow manual but am unable to find this warning in there.

*** WARNING Mass closure error exceeds 0.450E-04 after 69 timesteps.

I was getting this warning for every time step of my run.
I am trying to run my model with two open boundaries, Downstream and Upstream of the model.
Time series water levels are imposed on the down stream boundary.
Time series water levels and flow are imposed on the upstream boundary.

Any help on this will be much appreciated.

Thanks very much
abdulla.
RE: Delft3D-FLOW "Mass closure error" warning
Answer (Unmark)
4/30/14 1:42 PMas a reply to Abdulla Mohamed.
Hi Abdulla,

I had the same problem with my model. I am using domain decomposition for my models, and one of the domains gives the same warning " WARNING Mass closure error exceeds ...."

However, the simulation finished without any errors, and I am currently analysing the results.

So far I noticed that my results produces a lot of "noise" i.e. not smooth when compared to measured data.


I am going to re-run again my model with new parameters setting.

Anyone who can help us on this matter will be greatly appreciated


Best regards

Anas
RE: Delft3D-FLOW "Mass closure error" warning
Answer (Unmark)
4/30/14 10:39 PMas a reply to Anas Rahman.
Hi Anas,
thanks for your response
I have been trying different things, but have not been able to get rid of this warning just yet. But If I do find out something I will be sure to let you know.
Could you also let me know if you are able to find out why this warning happens.

Cheers,
Abdulla.
RE: Delft3D-FLOW "Mass closure error" warning
Answer (Unmark)
9/26/17 12:29 AMas a reply to Abdulla Mohamed.
Hello,

have any of you solved this warning? It seems like a problem of vertical decomposition, and I can only solve it when I change the number of layers.

I'll be glad with any help,
Rodrigo
RE: Delft3D-FLOW "Mass closure error" warning
Answer (Unmark)
10/12/17 5:10 PMas a reply to Rodrigo da Silva.
Hi Rodrigo,

1. Try to locate where the problems start (in space and time) and look if there is a reason for it. Try to solve it locally:
When it starts at a DomainDecomposition boundary, check that the grids are connected smoothly, without big jumps in the vertical, without big jumps in cell sizes.
2. What happens when you decrease the timestep? It should run more smoothly.
3. (Not nice, but may be helpful:) When the problems occur on a specific spot at a DomainDecompostion boundary, you can add viscosity locally to "damp" the effects.

Regards,

Adri