open TELEMAC-MASCARET The mathematically superior suite of solvers

Hi everyone,

I read in J-M Hervouet's book that it was possible to integrate equation of motion (and therefore working on the system corresponding to Saint-Venant equations) before the diffusion step (2nd dot page 148). This approach seems more appropriate when considering source terms computed with average velocity over the vertical such as friction terms using Chézy's law, am I right ? In this case, would anyone tell me how to proceed to adapt the steps ?

In advance, thank you.

Regards,

Marc

Hello Marc,

I am sorry but concerning TELEMAC-3D this book is a bit outdated.
I advise you to consult the new theory guide for TELEMAC-3D, which you can find here:
wiki.opentelemac.org/doku.php?id=documentation_v7p3r1

For 3D simulations, it is actually more accurate to work with the Nikuradse friction law, rather than a depth-averaged version of the friction. The latter is mainly kept for studies where the calibration was done in 2D and we wish to keep it in 3D, so as to avoid calibrating again.

Best regards,
Agnès

Hi Agnès, thank you for the quick answer

You're right concerning the friction law, Nikuradse's one is more relevant working directly in 3D. However, the thing is there are other source/sink terms computed according to an average velocity over the vertical, I am especially thinking of radiation forces due to waves. Am I right ? Furthermore, as far as I understood, the computational steps are the same in version v7p3 than in the previous ones.
I hope you see my point which might be not relevant I am just trying to understand the way it works

Best regards,

Marc