open TELEMAC-MASCARET The mathematically superior suite of solvers

Hi!
I ran my model and found the result still had some oscillations,so I add the "FREE SURFACE GRADIENT COMPATIBILITY =0.9".Then I found the result is more stable but the tidal range is larger than the result without this keyword.Why does this happen?

Hello captain,

Changing the value of the keyword FREE SURFACE GRADIENT COMPATIBILITY makes the computation of gradients of free surface different. That means the results may change and you may have to calibrate again.
That should be the case for you to my opinion.

Hope this helps,

Chi-Tuan

Hello Chi-Tuan,
Thank you for responding.
YES,you are right that I can calibrate again after I add the keyword "FREE SURFACE GRADIENT COMPATIBILITY".But there is another problem that the tide level and velocity can't be calebrated well with the same friction filed. That means that I must use one fricrion to calebrate the tide level and use another friction to calebrate the velocity.If there is a algorithmic problem in "FREE SURFACE GRADIENT COMPATIBILITY".
Best regards.

Hello captain,

When modelling tide with TELEMAC, do not forget that you have a few calibration coefficients dedicated to tide in addition to the friction coefficient:
- COEFFICIENT TO CALIBRATE TIDAL RANGE,
- COEFFICIENT TO CALIBRATE SEA LEVEL,
- COEFFICIENT TO CALIBRATE TIDAL VELOCITIES.

Hope this helps,

Chi-Tuan