open TELEMAC-MASCARET The mathematically superior suite of solvers

Dear all,

I´ve been trying to do a transient analysis with varied flow in TELEMAC where I have the following arrangement. I have a lake upstream, followed by a channel and then at the end I have a HPP Power House Intake. What I need to do is simulate a sudden stop of the turbines to analyse what are the waves formed in the channel by this situation. For doing so, I´ve used a prescribed water level upstream of my model (fixed and not varying with time) and a discharge downstream varying from a fix discharge to sudden zero.

The simulation appears to work almost perfectly but since I have a fixed elevation upstream when I set to zero the discharge downstream there is still inflow in the domain. This extra inflow makes my WSE at model increases to ~97.15 and my WSE upstream is 97,0m. Because of that I have a recirculation at my upstream boundary condition as the picsture attached.

My questions is, does anyone have a better boundarry condition arrangement do to this simulation?

Thank you in advance.

Marcus

Hello!

A combination that worked fine for me was:

1/ run a case where you have Q upstream and Z downstream; run until you reach a steady state.
2/ use the previous result in a restart procedure in which you keep Q at upstream but change the downstream BC from Z to Q (Qout = - Qin), which decreases quickly down to zero.

This way you can simulate both the continued inflow and the filling of the reservoir once you close the intake...

Good luck!

Regards
PL