open TELEMAC-MASCARET The mathematically superior suite of solvers

I am a new user of TELEMAC2D, and trying to invoke use of the LIQUID BOUNDARIES FILE to introduce an (upstream) discharge hydrograph. The problem is it won't move off initial conditions (t=0). The program runs with no errors and I obtain a results file with all zeroes. Starting with a level water surface and not advancing in time. I used the KEYWORDS, PRESCRIBED FLOWRATES (which apparently has replaced DISCHARGES) to invoke reading of the LIQUID BOUNDARIES FILE, but nothing seems to work.

Any assistance would be much appreciated, thanks!

john

Hello,

You should check your BOUNDARY CONDITIONS FILE and the lines corresponding to the boundary with your entering discharge should all start with 4 5 5, then ybe aware that the liquid bounadries have a numbering (their rank of appearance in the boundary conditions file) and may be several, and the keyword PRESCRIBED FLOWRATES is a series of numbers. For example if your domain is an horizontal rectangle with entrance at the left and exit at the right, boundary 1 is the exit and boundary 2 the entrance, so that you must write :

PRESCRIBED FLOWRATES : 0.;100. (for example)

This will probably help, otherwise I don't really know what happens, regards,

Jean-Michel Hervouet

Thanks for your reply. Yes I had the 4 5 5 in the BC file however the problem may lie in the fact that my U/S boundary starts at the top end of the file and owing to the way the channel configuration was drawn in Blue Kenue, continues in its numbering at the end of the file. Here is what I am getting now. The last input data read is my stage discharge rating table (you can see the last few entries), then when it comes time to read the LIQUID BOUNDARIES FILE, it stalls. My time step is 1 second.

Q= 149.19999999999999 Z= 31.399999999999999
Q= 199.69000000000000 Z= 32.399999999999999
Q= 258.30000000000001 Z= 33.399999999999999
Q= 325.42000000000002 Z= 34.399999999999999
Q= 401.43000000000001 Z= 35.399999999999999

CORFON (TELEMAC2D): 1 BOTTOM SMOOTHINGS

THE LIQUID BOUNDARIES FILE CONTAINS
14 LINES WITH:
Q(1)
STREAMLINE: USING PARALLEL VERSION OF CHARACTERISTICS 6.1
CVTRVF: 200 SUB-ITERATIONS REQUIRED FOR THE
VF SCHEME. DECREASE THE TIME-STEP

PLANTE: PROGRAM STOPPED AFTER AN ERROR
RETURNING EXIT CODE: 2
copying: jfpres.slf


My work is done

Hello,

This is certainly a high velocity somewhere, for example if the water depth is too small for the total discharge you want to enter, the velocities will be very large. Though I do not see the mesh size the time step seems reasonable but you could reduce it to do at least one time step and see what happens in the results and where is the problem.

By the way, how comes that you are a new user with version 6.1 ?

Regards,

JMH

Hello and thank you again for your reply. Indeed the depth is quite small but the velocity is low because of the mild channel slope. I will try adjusting the time increment in both the LBF and Steering File. I just wrote a quick uniform flow program to obtain a rating table....btw this TELEMAC2D version was on the pc provided me. Best Regards, john