open TELEMAC-MASCARET The mathematically superior suite of solvers

Hello

I am trying to get stable my model simulations in telemac 2D. However there are many instabilities in the model I set up.
For your reference I am forcing the model with the TPXO regional Pacific ocean
volkov.oce.orst.edu/tides/region.html

Attached you can see my steering file and the instabilities I have in my model simulations. The red line plotted the model results.

Do you have any recommendations to diminish the instabilities as soon as can.

Thank you
Joel

Hello,

It is not instabilities (it does not crash), rather wiggles that could be due to the inf-sup condition.

Try:

MASS-LUMPING FOR VELOCITIES = 1.

and/or:

COMPATIBILITY OF FREE SURFACE GRADIENT = 0.5

You can also check what kind of diffusion is given by the Smagorinsky model and try another one, like constant on the horizontal and mixing-length on the vertical. In this case you can tune the horizontal diffusion.

With best regards,

Jean-Michel Hervouet

Hello Jean
Thank you very much for your reply

I modified the parameters you suggested me and there is a error on screen. I just swift on the two variables you mentioned before.

... reading the main module dictionary

... processing the main CAS file(s)
runCAS:
uncontroled error from python:: KeyError('MASS-LUMPING FOR VELOCITIES',)
~~~~~~~~~~~~~~~~~~
Traceback (most recent call last):
File "C:\opentelemac-mascaret\v6p3\scripts\python27\runcode.py", line 713, in
runCAS
cases,lang,ncsize = processCAS(casNames,MODFiles[codeName],MODFiles[
codeName])
File "C:\opentelemac-mascaret\v6p3\scripts\python27\runcode.py", line 234, in
processCAS
cas = readCAS(scanCAS(casFile),dico,frgb)
File "C:\opentelemac-mascaret\v6p3\scripts\python27\parsers\parserKeywords.py"
, line 145, in readCAS
kw = frgb[kw]
KeyError: 'MASS-LUMPING FOR VELOCITIES'
~~~~~~~~~~~~~~~~~~

Thank you
Joel

Hello,

Sorry I just took the example commented out in your own steering file, and it was misleading, as it is meant for Telemac-3D, in Telemac-2D it is:

MASS-LUMPING ON VELOCITY

This should be harmonised some day...

Regards,

JMH