Really high velocitys in 3D sim. low waterlvl Error: conjugategradientSAAD - Forum - Delft3D Flexible Mesh
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Really high velocitys in 3D sim. low waterlvl Error: conjugategradientSAAD
S Stelljes, modified 2 Years ago.
Really high velocitys in 3D sim. low waterlvl Error: conjugategradientSAAD
Youngling Posts: 2 Join Date: 6/21/22 Recent Posts
Hi,
I setup a model with Delft3D FM at a coastal area. In 2D everything works fine, but now I did the same simulation in 3D with 10 sigma layers. In every simulation i did in 3D simulation the same error occurs: conjugategradientSAAD. The simulation works for almost 4 days and then aborts.
I have noticed that the velocitys in the areas of low waterlevel are getting really high at some single points. The highest is like more than 200 m/s. You can see it in the attached picture. The problem with the high velocitys is espacially at the borders where the really low waterlevels are, you can see it in picture "error2".
I think I have to change some of the model settings. Maybe the numerical parameters or the advanced ones. So far I am doing all the simulation with default values. In 2D it worked fine.
Does someone know what to do and why this error occurs?
I setup a model with Delft3D FM at a coastal area. In 2D everything works fine, but now I did the same simulation in 3D with 10 sigma layers. In every simulation i did in 3D simulation the same error occurs: conjugategradientSAAD. The simulation works for almost 4 days and then aborts.
I have noticed that the velocitys in the areas of low waterlevel are getting really high at some single points. The highest is like more than 200 m/s. You can see it in the attached picture. The problem with the high velocitys is espacially at the borders where the really low waterlevels are, you can see it in picture "error2".
I think I have to change some of the model settings. Maybe the numerical parameters or the advanced ones. So far I am doing all the simulation with default values. In 2D it worked fine.
Does someone know what to do and why this error occurs?
Attachments:
S Stelljes, modified 2 Years ago.
RE: Really high velocitys in 3D sim. low waterlvl Error: conjugategradientS
Youngling Posts: 2 Join Date: 6/21/22 Recent Posts
Update: After running a lot of simulations, I found that the error message no longer occurs when I change the Solver Type as follows:
Solver Type:
sobekGS + Saadilud --> sobekGS
The simulation runs through with the changed setting, but there remains an error in the model. The depth-averaged velocities become unrealistically high in some cases, in that cells where a dry cell is flooded. However, this error only occurs in the depth-averaged velocities. Because of this error, the error message probably appeared with the other solver. In the velocities of the individual layers the error with the high velocities does not appear at any time.
I would be glad if someone can enlighten me why these unrealistically high velocities partly occur when flooding a cell.
Thanks a lot!
Solver Type:
sobekGS + Saadilud --> sobekGS
The simulation runs through with the changed setting, but there remains an error in the model. The depth-averaged velocities become unrealistically high in some cases, in that cells where a dry cell is flooded. However, this error only occurs in the depth-averaged velocities. Because of this error, the error message probably appeared with the other solver. In the velocities of the individual layers the error with the high velocities does not appear at any time.
I would be glad if someone can enlighten me why these unrealistically high velocities partly occur when flooding a cell.
Thanks a lot!