open TELEMAC-MASCARET The mathematically superior suite of solvers

Hello,

I would like to manage a boundary with stage-discharge curve at the exit of a flume.
I did the following steps :

In the parameter file, I added the keywords :
STAGE-DISCHARGE CURVES = 0;1
STAGE-DISCHARGE CURVES FILE ='ZQcurve.txt'

For the initial elevation, I put the the first elevation of my stage-discharge curve, which correspond to a discharge of zero.
PRESCRIBED ELEVATION = 0.0;22.87

In the boundary conditions file, I chose : LIHBOR=5 ; LIUBOR=5 ; LIVBOR=5 for the nodes of this boundary (which is the boundary number 2).
Here is an extract of it :
2 2 2 0.0 0.0 0.0 0.0 2 0.0 0.0 0.0 116 801
5 5 5 0.0 0.0 0.0 0.0 4 0.0 0.0 0.0 918 802
5 5 5 0.0 0.0 0.0 0.0 4 0.0 0.0 0.0 460 803

My stage-discharge curves file is built as explained in the user manual :
#
# STAGE DISCHARGE CURVE FOR BOUNDARY 2
#
Q(2) Z(2)
m3/s m
0.000 22.870
1.000 23.510
2.000 23.605
3.000 23.697
4.000 23.785
5.000 23.870

Did I miss something ? Because my case doesn't give relevant results. It seems that the boundary condition take the prescribed elevation as a constant elevation instead of using the stage-discharge curve file.

Thank you by advance for any help.

Benoit D.

Hello,

If your boundary is an exit, I think the discharge should be negative. This may explain the problem.

Depending of what you are doing, it could be that Thompson boundary conditions also work.

WIth best regards,

Jean-Michel Hervouet