open TELEMAC-MASCARET The mathematically superior suite of solvers

Hello All,

I am running a simulation of Telemac-3D along with sediments. I have completed 1st simulation and the 2D-result file is written with following variables, Velocity, Water Depth, Free Surface, Mud & Bed Evolution.
Now when I try to start the further simulation with this 2D-result file as previous computation file using computation continued, Other variables are considered properly. However, the Bed Evolution is getting to Zero (0) at the computation continued simulation which is not the final step value of the 1st simulation.

Can anyone please help me in this to get proper value of bed evolution in computation continued?

Thanks in advance...

Regards,

Kanak

Hello Kanak,

How do you model sediments with TELEMAC-3D?
- coupling with GAIA,
- coupling with SISYPHE,
- using SEDI-3D/sediment part of TELEMAC-3D? I have the feeling that you use this last method.

As I have just written to André Renault here:
opentelemac.org/index.php/kunena/17-sisy...-sediment-file#42982

I pushed a new feature for GAIA a few days ago on the main: RESTART MODE as it was done for TELEMAC-2D last year (for release v8p4) and for TELEMAC-3D for a few years.

This feature enables 2 main things:
- automatically saving of every necessary variable needed to continue a GAIA computation coupled with TELEMAC-2D or TELEMAC-3D in a specific file (RESTART FILE) during the 1st computation,
- reading of a previous computation file with every variable necessary for a good continuation without loss of accuracy in 2D (perfect for most of the examples and nearly perfect in 3D). If the variables are not in the previous computation file (e.g. not a RESTART FILE), some variables can be initialised by 0 or other ways (but there will be loss of accuracy).

Anyway, I think it is a good basis for you and should use GAIA.

For more descriptions, you can read:
- issue #899: gitlab.pam-retd.fr/otm/telemac-mascaret/-/issues/899
- MR !121: gitlab.pam-retd.fr/otm/telemac-mascaret/-/merge_requests/121

If coupling with GAIA, I would suggest you to use the main (waiting for next release v8p5 which is planned to be ready early December).


Indeed, when continuing a computation from a 2D result file, only water depth, horizontal velocity components and bottom elevations are read.

Anyway, to use Bed Evolution from a previous 2D result file, I think you have to add one line in TELEMAC3D_INIT before CALL READ_DATASET(T3D_FILES(T3DS2D)%FMT,T3D_FILES(T3DS2D)%LU...

ALIRE2D(37) = 1
and after the call back to old value 0:
ALIRE2D(37) = 0

Moreover, you may have to change CONDIS a little bit:
Add SUIT2 to the list of USE DECLARATIONS_TELEMAC3D, ONLY : H,Z,NPLAN,SUIT2

Add a condition around:
to be changed toso that in case no 2D continuation, the variable is initialised to 0. Otherwise, read from FILE FOR 2D CONTINUATION.

Hope this helps,

Chi-Tuan

Hello Chi-Tuan,

Thank you so much for the helpful response.

Yes, I am modelling sediments with TELEMAC-3D & SEDI-3D. I have modified the TELEMAC3D_INIT & CONDIS as you suggested. After these modifications, the initiation of the Bed Evolution for computation continued has started.

However, the value immediately falls down to Zero at the same time step and not following the profile which will be observed if the computation continued is not opted for the simulation. The plot of the same is attached for the reference. (In the Plot RED line is representing Simulation-1 while Blue Line is computation continued Simulation-2)




Is the another call of "CALL OS('X=0 ',X=S3D_ESOMT)" under Mass Balance from 'TELEMAC3D_INIT' is interfering the same?




Can you please guide in this regard??

Thanks again.

Regards,

Kanak

Hello Kanak,

I think you guess it right. As S3D_ESOMT is a cumulative value, it should not be initialised to 0 when do a continued computation. You can delete the line in the Fortran file or add a condition IF(.NOT.SUIT2) THEN... the initialisation... ENDIF

Chi-Tuan

Hello Chi-Tuan,

Thanks for the guidance and sorry for late response. I was trying the said modification and other modifications to achieve the required computation continued.
I have modified 'S3D_ESOMT' in telemac3d_init.f as discussed in earlier reply, the value of Bed Evolution is now not falls down to Zero at the same time step. But, still it is not following the profile which will be observed if the computation continued is not opted for the simulation. The plot of the same is attached for the reference. (In the Plot RED line is representing Simulation-1 while Blue Line is computation continued Simulation-2).






I am going through various dependent subroutines for the same but unable to identify the exact cause for the same.

Can you please suggest/ guide in this regard?

Thank you.

Regards,

Kanak

Hello Kanak,

As told in one of my previous posts, if you want to get a better continuation computation, you should move to TELEMAC-3D coupled with GAIA and use the current main. Work has been done for most cases.

Otherwise, look at what has been implemented and try to reproduce it for SEDI-3D but I am not sure it will be easy.
For sure, in your version, some special variables have not been saved in the previous computation file.

Good luck,

Chi-Tuan

Hello Chi-Tuan,

Thank you so much for the guidance. I will explore the Telemac3d+GAIA option.

Thanks again.

Regards,

Kanak