open TELEMAC-MASCARET The mathematically superior suite of solvers

Hi

I have a question about tidal flats. This only has to be activated if I want to simulate my river flowing into the sea/lake?
I have only a river and a Source (both with 4 Tracer). The aim is to get a steady state water flow after 12h. The tidal flats must be deactivated or? My problem is that if I activate tidal flats, my simulation will work, but will crash if I disable it.

Does anyone have a solution?

SCHEME FOR ADVECTION OF depth = 5
SCHEME FOR ADVECTION OF k-e = 1
SCHEME FOR ADVECTION OF TRACERS = 5;5;5;5
SCHEME FOR ADVECTION OF velocity = 1

TIDAL FLATS = false
TREATMENT OF NEGATIVE DEPTHS = 2

Best regards,
Vittel

Hello

You can reach steady state independently of tidal flat activation.
Activating tidal flats depend excusively on your model and your choice. If the model includes wet elements that could get dry or dry elements that could get wet, you need absolutely to activate tidal flats. You can choose to cut the domain before these elements and then you will have no need fot such option.

If you activate tidal flats, you need to use advection scheme that handles such option. You can choose scheme 13 or 14.

Please refer to user manual for more inputs.

kind regards

Riadh

Hi Riadh,

thank you for your answer.
I do not understand why my water elevation on the riverbed is higher than in the middle of the river. I thought it was because of the tidal flats (I used scheme 14). I have to set my inital water elevation to 99m, because the inlet is 10 km above and I do not want to have a dry boundary condition. My discharge is only 60m³/s. The water elevation drops from 99 m to 96 m. If I add concentration, then the concentration stays at 0 at the riverbed, where the water elevation is higher than the 96m. So I thought that I had to deactivate tidal flats so that the water at the riverbed would not be held back.

Best regards

It could be just a combination of:
1- coarse mesh at that location (river back)
2- postprocessing algorithm which consider the big element as completely wet (while it is partially wet).

conclusion: yes it is the tidal flat which causes this unconsidtancy but also, it is the effect of a coarse mesh and a mis-interpretation of the post-processor.

kind regards

Riadh

Thank you for your answer.
Unfortunately, I can not refine the grid because my data base in this areas is very bad. But I would like to test a simulation in which I disable the tidal flats. But if I do this with the data from the first post, then the simulation stops. Do you know why?
Best regards

What kind of error message do you have ?
please try to post a screen snapshot .


Riadh

here is the log-file

It is a problem of initialization. Your vertical discretization is wrong.
It is linked to the vertical mesh transformation, I would suggest to use a generalized sigma transform (keyword MESH TRANSFORMATION=2) which is given using Zstar variable.

I hope this helps

kind regards

Riadh

OK I have done it: MESH TRANSFORMATION=2

In the manual I have read that I should set TRANSF_PLANE = 2 in the CONDIM subroutine. I found these in the following folder.

...\opentelemac-mascaret\v7p2\sources\telemac3d\condim.f

Is this the right file?
In the file I have set the following (I tried 2 different ways):

a)
DO IPLAN = 1,NPLAN
TRANSF_PLANE%I(IPLAN)=2
ENDDO

b)
DO IPLAN = 1,NPLAN
TRANSF_PLANE%I(IPLAN)=2
ENDDO
ZSTAR%R(1)=0.0D0
ZSTAR%R(2)=0.05D0
ZSTAR%R(3)=0.1D0
ZSTAR%R(4)=0.15D0
ZSTAR%R(5)=0.3D0
ZSTAR%R(6)=0.6D0
ZSTAR%R(7)=0.8D0
ZSTAR%R(8)=1.D0

Unfortunately, the simulation continues to break off in both different ways.

Best regards
Vittel

Hello

You have to read the listing. It is written explicitly what is the problem.
Moreover, please read the user manual that explains which options you should use for each mesh transformation.

Finally, the best way to start with Telemac-3d is to adapt an existing valdiation case. So choose the case which resemble the most to your case in the folder examples/telemac3d and then adapt it to your files.

with my kind regards

Riadh