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

NaN Error

JD
João Dias dos Santos, modified 7 Years ago.

NaN Error

Youngling Posts: 2 Join Date: 4/5/13 Recent Posts
I'm trying to run a flow model using only astronomic forcing. I can run this scenario if I use the time of one day, if I increase the simulation time I get this error in more or less steps depending the time step I set. It usualy "exits abnormally" when it's 96.4% or 19.3% left.

*** MESSAGE No Fmtbnd record found in MDF-file, item will be skipped
*** MESSAGE No Fmtsta record found in MDF-file, item will be skipped
*** MESSAGE Executable for 32-bits platform.
*** MESSAGE Double precision computation using reals of kind 8
*** MESSAGE No Fmtcco record found in MDF-file, item will be skipped
*** MESSAGE No Fmtgrd record found in MDF-file, item will be skipped
*** MESSAGE No Fmtbnd record found in MDF-file, item will be skipped
*** MESSAGE Local time zone is UTC - 3.0 hours
*** MESSAGE Using UNESCO density formulation by default
*** MESSAGE Momentum solver cyclic method is specified
*** MESSAGE DRYFLP and DPSOPT both specified in MD-file. Using DPSOPT: MAX
*** MESSAGE Transport solver cyclic-method method is specified
*** WARNING File will not be created - Inconsistent comm. file times
*** MESSAGE Nodal factors updated at 2013-04-05 00:00:15.0000
*** MESSAGE Nodal factors updated at 2013-04-05 06:00:15.0000
*** MESSAGE Nodal factors updated at 2013-04-05 12:00:15.0000
*** MESSAGE Nodal factors updated at 2013-04-05 18:00:15.0000
*** Restart file written at 1440.0000 minutes after ITDATE
*** MESSAGE Nodal factors updated at 2013-04-06 00:00:15.0000
*** MESSAGE Nodal factors updated at 2013-04-06 06:00:15.0000
*** MESSAGE Nodal factors updated at 2013-04-06 12:00:15.0000
*** MESSAGE Nodal factors updated at 2013-04-06 18:00:15.0000
*** ERROR NaN found after 5556 timestep(s).
*** ERROR Flow exited abnormally
JL
João Lencart e Silva, modified 7 Years ago.

RE: NaN Error

Padawan Posts: 71 Join Date: 3/30/11 Recent Posts
It may be some instability on your grid which builds up untill it crashes the run.
* Check all grid design conditions (orthogonality, smoothness, aspect ratio...)
* Check your CFL condition
* Check for unsmooth bathy
* Check your water level and velocity in the trim and trih files for instabilities.

Hope this helps.

João.
JD
João Dias dos Santos, modified 7 Years ago.

RE: NaN Error

Youngling Posts: 2 Join Date: 4/5/13 Recent Posts
João Lencart e Silva:
It may be some instability on your grid which builds up untill it crashes the run.
* Check all grid design conditions (orthogonality, smoothness, aspect ratio...)
* Check your CFL condition
* Check for unsmooth bathy
* Check your water level and velocity in the trim and trih files for instabilities.

Hope this helps.

João.


Well all I had to do was to change all boundary types to "water level". Before that I was using one boundary as Rieman because my teacher said that one of the boundaries should be of a different type to achieve more accurate results. Is it ok to run flow/wave/morphology model with all boundaries with the same type, in this case "water level"?
WN
Wendy Ni, modified 7 Years ago.

RE: NaN Error

Youngling Posts: 3 Join Date: 12/20/11 Recent Posts
Hi,

I have similar question in running model with space varying wind field. I gave 3 correspording files namely #u_wnd.amu#,#v_wnd.amv#,#p_wnd.amp# in Additional Parameters data group. And when I run the model, these is an error "*** ERROR NaN found after 1 timestep(s)". I check the file and have no idea where is wrong. Could you please help me.
Thank you in advance.

Wendy
Qinghua Ye, modified 7 Years ago.

RE: NaN Error

Jedi Council Member Posts: 610 Join Date: 3/2/11 Recent Posts
Hi Joao and Windy,

The info you provide is not enough to judge... I listed some tips to check your model here.

Did you also try to run the model without the atmospheric conditions? Did you also check the tri-diag file?

Regards,

Qinghua