open TELEMAC-MASCARET The mathematically superior suite of solvers

Dear TELEMAC users,

I want to couple a Cellular Automata (CA) model with telemac2d so that it also works in parallel.

The CA model will have rectangular grid cells and a finer grid resolution than the TELEMAC model.

The general idea is that e.g. the output of the CA model is coupled with T2D e.g. every 10th timesteps e.g. influencing flow via the dragfo-subroutine.

I was planning to couple CA nodes with the closest T2D node by using something like a connectivity table.

Is there an easy way to create this connectivity table e.g. using PARTEL??

How do I need to set the coupling up that it also works in parallel(my T2D model has a very big domain)??
I was thinking of assigning Xmin,Xmax,Ymin,Ymax using my T2D domain, so that maybe the domain would be decomposed in similar sub-domains when running in parallel, is that possible? What other solutions would be available??

Best Regards,
Christian

Hi Christian

As your problem is complex, I would advise you to start working with serial computation first in order to well manage the coupling before moving to parallel computation.
Just to well understand your objective:
You CA model will be a rectangular box which will be include inside the unstructured mesh of Telemac.
Then I don't think partel will be useful to generate the connectivity table.
I imagine you could do that with a pre-processing python script; but you should first define how looks this connectivity table

When you will move to parallel computation, you will probably have 2 options:
one with the use of the global numbering in each subdomain, the other with a pre-processing of the global connectivity table to a local connectivity table in partel (this is a little bit more complex)

Hope this helps

Dear Christophe,

Thank you for your advice.

I started now to couple it in serial and decided as a first test to use a 2d polynomial interpolation to transfer the CA models results(structured rectangular grid) onto my T2D grid.

I have one question regarding print statements in Telemac2D. I wrote the CA model in the dragfo subroutine, since that is also were the interactions with T2D will take place(called at every timestep), and want to print the CA model output using the statement:


open(1, File='test.dat', status='unknown', form='unformatted',
& access="stream")
write(1) real(sizeX,8),real(sizeY,8),real(NumStored+1,8),
& real(jjjk,8), Cells


When the code arrives there I get the error message:
LIT: ABNORMAL END OF FILE ONE INTENDED TO READ A RECORD OF 32 VALUES OF TYPE: CH ON LOGICAL UNIT: 1

I do see the output-file test.dat in my temporary folder, but also there the values are not what I expect.

Do I need to add something for writing the output? e.g. change something in T2D printing subroutines?

Best Regards,
Christian

Hi

This is due to the chosen number (1) which is probably already used.
Try with 99 instead.
Otherwise, you could use some dedicated keyword for user result file:
FORMATTED RESULT FILE or BINARY RESULT FILE (look in the dico to check the exact spelling)

Regards