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: Simulation results are not smooth / double peaks

Anas Rahman, modified 3 Years ago.

Simulation results are not smooth / double peaks

Youngling Posts: 21 Join Date: 10/4/13 Recent Posts
Hi everyone,

I am using domain decomposition for my models, with a combination of Water Level and current for my boundaries. I am currently trying to calibrate my model with measured data. However, results from my simulation are not smooth /jagged and showing double peaks.It is in my understanding that models should give a smooth graph, while measured data supposedly be uneven/not smooth due to interference ect

I am running a 3D model, and interested in the horizontal velocities (U and V components). I would like to highlight that my results matched quite well with the measured data in term of the phases, and also the velocities value. The only things that is bothering me is the uneven graph that my models produced.

A sample of my result is attached together with this post.

Any help in this matter is greatly appreciated!
domain decomposition tide
Fernando Barreto, modified 3 Years ago.

RE: Simulation results are not smooth / double peaks (Answer)

Padawan Posts: 72 Join Date: 6/21/12 Recent Posts
Hi, What type of boundary condition are you working with? Velocity and water levels in different boundaries (for instance in the north velocity, and in east current) or Riemann bc?
If it's the first type, are you using Riemann coefficients to absorb the outgoing waves?

Regards,
Fernando
EE
Esther Espinoza, modified 4 Months ago.

RE: Simulation results are not smooth / double peaks

Padawan Posts: 25 Join Date: 4/6/17 Recent Posts
Fernando Barreto:
Hi, What type of boundary condition are you working with? Velocity and water levels in different boundaries (for instance in the north velocity, and in east current) or Riemann bc?
If it's the first type, are you using Riemann coefficients to absorb the outgoing waves?

Regards,
Fernando


Hi, I'm having the same problem with my water level results. Do you know what it might be? I don't know how to solve it. I'm using water level with time series for one open boundary in an estuary. I changed my manning coefficient between 0.012 and 0.030 and the eddy viscosity between 10 and 100. For the reflection parameter alpha I used 0 and 100 but with all the above I still have the same problem. I'm not sure what I'm doing wrong. I'm not considering other parameters just water level.

Thanks!
Adri Mourits, modified 4 Months ago.

RE: Simulation results are not smooth / double peaks (Answer)

Yoda Posts: 1150 Join Date: 1/3/11 Recent Posts
Hi Esther,

Does it help if you reduce the timestep with a factor 10?

Regards,

Adri