open TELEMAC-MASCARET The mathematically superior suite of solvers

Hi all,
just a question. I do the simulation of wetland. During a simulation, i have a strange temporal variability of velocity direction. Second by second, the direction in a singol node of mesh changes the direction and i don't arrive to a situation of stability, when the velocity is stable,more or less.
Can someone give me some advice?
Thanks.

Hello,

Difficult to say with these elements. Do you have tidal flats and is it near a tidal flat ? Note that on nearly dry land the velocity corresponds to very small discharges, and may not be very significant. A few years ago we identified and corrected a non linear behaviour that resulted in successive velocity and no velocity on a dry point, because no velocity gave no friction and no friction gave velocity, and velocity on a dry zone gave infinite friction and infinite friction gave no velocity and so on... This is now settled but it showed that the very complex form of friction terms in 2D (in U**2/H) could give a very complex behaviour.

With best regards,

Jean-Michel Hervouet

Hi,

with OPTION FOR THE TREATMENT OF TIDAL FLATS = 2 , the velocity comportament improves itself.

With best regards.

Sorry,but my problem persists. Near the boundaries, the velocity changes direction over time, second by second. Can the problem be Elder turbolence model?

With best regards.