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Hi,
I'm trying to modelize a large bridge( 30m x 3m) with tubes(9) but even with a low flow i have a meaningful discharge. (-0.30 m for Q = 50m3/s)
How decrease this discharge to approach a simple open for low flow ?
( I try to modify parameter (L12 CE1 CS1 ... ) unsuccessful ..)
Thank you for your attention

nb: this brige was submerged with a flow Q=150m3/s
nnb: sorry for my approximate english

Jean-Paul

Hi
When the flow is open in tubes, the computation is made according to a weir law so you should try to adjust parameters but this is maybe a "wrong" approximation in your case...

Regards

Hi Jean-Paul,

if you look in the code how the discharge is calculated, you can see which terms you can change to decrease the discharge.

You could decrease the section (= make a smaller tube). Make sure that you divide your entire section under your bridge over your 9 tubes and not give every tube the full section.
You could increase the head loss, but from your post it seems you already played with these parameters.

You could divide your discharge by the section of your space under the bridge to see if the velocities you have are out of a normal range.

Hope this helps
if not you should specify your problem further.

Regards,

Sven