open TELEMAC-MASCARET The mathematically superior suite of solvers

In buse.f, flow through culvert can be limited by available water in node 1 or 2.
gitlab.pam-retd.fr/otm/telemac-mascaret/..._type=heads#L584-591

I think it would be great to warn user when this limitation is reached as it could lead to false results.

Agreed that this would be a useful addition.

Currently working on culvert modelling at the moment and something I also noticed going through the source code.

Hi
Cold you explain how the results could be false due to water availability limitation?
This specific treatment had been added to avoid some problems of instability when water volume is small relatively to computed discharge...

If such problems occurs, this could be linked to the local mesh size comparatively to the culvert size...

Regards

Hi Christophe,

I understand its a necessary requirement to avoid the instabilities but I can also see how someone may be misled by the cell volume limited discharges in the event this condition is triggered.

In my case, I output the computed discharges to a text file with a flag if this condition is triggered - just to make sure I have sufficient cell volume.

Hi Christophe,

Absolutely !
I fully understand why it has been coded this way and it is indeed a user mistake.
But many user don't dive into source code to know how it works and just trust the code.

In case of a big culvert linked to small mesh, the culvert will never reach its full capacity as it will be caped by available water and final head loss will be greater than reality.
User should double checks computed flow with analytic formula (simple orifice formula is enough for pressure flow) but many don't do that.

That's why a warning could be great when flow is limited by available water just to warn user that what's wrong in his model design.