open TELEMAC-MASCARET The mathematically superior suite of solvers

Dear all,
I'm trying to model a gate flow in a cemented bed channel. The flow that I modeled is going fast because I did not consider the gate and I imposed a hydrograph at an upper section of the gate. We measured the gate-opening height during the flow so I have to impose the Hg(t) of gate level.
With a 1D code we wrote as shown hereafter. I appreciate any help to adapt this for Telemac.
And for this, I just need to modify only the Fortran file?

REAL(8) HGATE
IF(AT.LE.28D0) HGATE=-0.048D0*AT+2.152D0 !HGATE is the gate height
IF(AT.GT.28D0) HGATE=-0.01D0*T+1.08D0 !YAM is the water depth behind the gate
IF((T.LE.3D0).AND.(H%r.GE.HGATE)) !
Q%r=12.95D0*(H%r-HGATE)
IF((AT.GT.3).AND.(H%r(I).GE.HGATE))
Q%r=4.078*(H%r(I)-HGATE)**0.447

Thanks in advance,
Gashin

Hi
Is the gate a part of your model? or just at the upstream section of it?
Try to explain more in detail or with an image what do you want to do exactly.
With telemac2D, you cannot model the flow under a gate flow...

regards

Hello,

Please also detail what you aim to do and where the following code is supposed to be, I see many potential problems in it.

REAL(8) HGATE
IF(AT.LE.28D0) HGATE=-0.048D0*AT+2.152D0 !HGATE is the gate height
IF(AT.GT.28D0) HGATE=-0.01D0*T+1.08D0 !YAM is the water depth behind the gate
IF((T.LE.3D0).AND.(H%r.GE.HGATE)) !
Q%r=12.95D0*(H%r-HGATE)
IF((AT.GT.3).AND.(H%r(I).GE.HGATE))
Q%r=4.078*(H%r(I)-HGATE)**0.447

With best regards,

Jean-Michel Hervouet

Thank you very much for your reply.

In fact the principal aim is to simulate a real case of flush flow the same as “dam-break” phenomenon and then sediment transport. You can see in the figure that in IC I imposed a water head of 2.15m before the gate as measured and a water level of 0.45 m for 1100m downstream. The channel has a slope of 0.008%. Available channel topography of upper part is just 50m, that’s why I imposed also a measured hydrograph in -50m from the gate for BC. The gate is a weir function (downstream control type) and its opening procedure is time-taking as you can see the graphic, it takes around 1min to be completely opened. The opening shows two trends so two equations. For this reason, I want to delay the gate evacuating by imposing these two equations for the first 1min of discharging. And after 1min, I allow the flow evacuate/continue “normally”. Because we checked the sediment transport evolution that was quickly due to the rapid evacuation of the flow.
Please let me know if I am clear to send you more details.
Thanks in advance

Hi
Sorry but I don't understand the IC figure...
Could you make a drawing of your problem (based on your mesh for example) with the various indications?

Regards

Hereafter you can see the detailed images.

Hi,

wouldn't it be much easier to cut of the "gate" and start with an input hydrograph as usual?

Regards,
Gabi

Hi Gabi,
Thank you for response.
In fact we don't have measured hydrograph in gate location. just in -50m from the gate.
Let me know if I'm clear.

Regards,
Gashin

Hi

Gabi's solution is probably the easiest one. You just have to compute the evolution of the discharge at the gate and impose it at the upstream boundary of your model which should be relocated just downstream the gate.

Nevertheless, as you mention the sediment transport, if you are also interested in the sediment on the reservoir, this will be more complicated as we don't have any regulation structure available inside Telemac.
This mean you will have to develop your own subroutine to manage the interface between the two parts of the model.
If you have a good fortran and Telemac knowledge it's possible. I think you should manage the gate as 2 boundaries condition with impose discharge (like the weir solution works). Then you compute the discharge according to the local condition and the opening and impose this value with a minus sign upstream the gate and with a positive sign downstream.

Hope this helps

Many thanks for this clarification about Telemac function. I will check this points and try to introduce in my model to see if it works.

Regards,
Gashin