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

Limit of Porous Plate's Closs

Eduardo G-Gorbeña, modified 1 Year ago.

Limit of Porous Plate's Closs

Youngling Posts: 6 Join Date: 8/8/14 Recent Posts
Hi all,

I want to model the effect of a tidal current turbine on hydrodynamics. I'm doing it modelling the tidal turbine as a porous plate. Assessing the simulation results, I notice that once you pass a threshold you can increase the value of Closs that it won´t generate an additional head loss (i.e. results for Closs = 100 are the same as for Closs = 1000). Even though I use a large Closs the flow through the cell is not complety block.

Does anyone know how I can change this limit?

Regards,

Eduardo
Phil Shepperd, modified 1 Year ago.

RE: Limit of Porous Plate's Closs

Padawan Posts: 33 Join Date: 5/31/11 Recent Posts
Hi Eduardo. While not specifically answering your question ....... I managed to calibrate Closs against some downstream flow speeds provided by my client, with the Closs values ending up <1, not 100 and i agree that the flow reduction diminishes as Closs increases. All worked fine when flow was perpendicular to the plate, but when i tried putting the flow at ~45 degrees to the plate, the wake recovery was way to quick, even with plates in both the M and N directions. In the end this was got round by putting plates in the cells either side of the cell in question, with Closs = 0.00001. Not sure what was gong on, but it worked well.
Eduardo G-Gorbeña, modified 1 Year ago.

RE: Limit of Porous Plate's Closs

Youngling Posts: 6 Join Date: 8/8/14 Recent Posts
Hi Phil,

Thank you for sharing your experience using poous plates, It is good to know how you solved the issue regarding oblique flows.

Regards,

Eduardo