open TELEMAC-MASCARET The mathematically superior suite of solvers

Hi,
I took a rectangular domain of size 2000X500(m) with 4 sides (two open boundaries and two solid boundaries). One of the open boundaries(l.h.s) is given with tidal flow condition and the other open boundary(r.h.s) with negative flow discharge. I conducted 4 cases with four different time steps(1sec, 2sec, 4sec and 5sec) by keeping the rest of the solver options same. I could observe inconsistencies in water depth near the discharge boundaries with change in time-step!

I have attached case related files and the image file of the plot that shows the VARIATION OF WATER DEPTH at the node 1549 (near the discharge boundary) for four different time-steps(1sec, 2sec, 4sec and 5sec). In particular, i would like to emphasize on the case with time-step 2sec, where the variation of water depth frequency is very high as compared to that of the other cases.

I am very curious to know the reason for such inconsistency in results.
Has anyone faced such problem before in simulation, or is it an expected behavior.

Thanks in advance,
Sathya

Hello,

One thing to look at first is whether you case is supercritical or not. If yes you may have a behaviour like this as the problem is not well posed and you may find multiple solutions at the entrance.

With best regards,

Jean-Michel Hervouet