open TELEMAC-MASCARET The mathematically superior suite of solvers

Hi everybody!
I'm modeling a domain constituted by an inflow that varies in time (upstream boundary) and the sea (downstream boundary). Here there 2 questions:

1) In the upstream boundary in BlueKenue I selected the option "prescribed Q", while in the other one "prescribed H": is it correct?
2) I realized a file "hydro.liq" in which I have put the time, the discharges and some values of SL, as explained in the manual, but I have not well understood the real meaning of them. Can you briefly tell me what they are?

I tried to run Telemac2D, but it stops after few seconds with the following error:

CALLING BORD
DEBIMP : PROBLEM ON BOUNDARY NUMBER 2 (*the upstream*)
GIVE A VELOCITY PROFILE
IN THE BOUNDARY CONDITIONS FILE
OR CHECK THE WATER DEPTHS

Thank you in advance!

Hello

very probably, the boundary where Q is prescribed is dry. Telemac-2D does not accept that case. Thus try to start with wet boundary (initial water depth = ... )

The file you are using allows the prescritption of boundary conditions varying in time. Telemac will interpolate the value of Q and SL at each time during the run. Read more carefully the user manual, it is well explained.

with my best regards

Riadh ATA

Hello riadh, thank you for your suggestions.

I changed the initial water depth as you told and the program runs for a brief period, but after some iterations it gives me the previous error. Besides, it correctly runs when the number of time steps and the graphic printout period are low.

Anyway, here are the parameters of my cas.file:

---

BOTTOM SMOOTHINGS =1
FRICTION COEFFICIENT =0.06
LAW OF BOTTOM FRICTION =4
TURBULENCE MODEL =3

/ EQUATIONS, BOUNDARY CONDITIONS
VELOCITY PROFILES =1;1
OPTION FOR LIQUID BOUNDARIES =1;1

/ EQUATIONS, INITIAL CONDITIONS
INITIAL DEPTH =0.1
INITIAL CONDITIONS ='CONSTANT DEPTH'

/ INPUT-OUTPUT, FILES
SECTIONS INPUT FILE ='control_section.txt'
LIQUID BOUNDARIES FILE ='hydro.liq'
GEOMETRY FILE ='geometry.slf'
SECTIONS OUTPUT FILE ='output3.txt'
STEERING FILE ='bisagnoSS.cas'
BOUNDARY CONDITIONS FILE ='bc_bisagno.cli'
RESULTS FILE ='results3.slf'

/ INPUT-OUTPUT, GRAPHICS AND LISTING
VARIABLES FOR GRAPHIC PRINTOUTS =U,V,B,H,F,S
MASS-BALANCE =true
GRAPHIC PRINTOUT PERIOD =50

/ NUMERICAL PARAMETERS
CONTINUITY CORRECTION =true
DEBUGGER =1
NUMBER OF TIME STEPS =300
TREATMENT OF THE LINEAR SYSTEM =2
SUPG OPTION =1;1;1;1
COMPATIBLE COMPUTATION OF FLUXES =true
TIME STEP =5.
INITIAL TIME SET TO ZERO =true

/NUMERICAL PARAMETERS, SOLVER
SOLVER =1
SOLVER ACCURACY =1.E-3

---

And this is my liquid boundaries file:

#
T Q(2) SL(1)
s m3/s m
0 20.0 3.0
5000 20.0 3.0
10000 20.0 3.0
15000 100.0 3.5
20000 100.0 3.5
25000 20.0 3.0
30000 20.0 3.0
35000 50.0 3.3
40000 20.0 3.0
45000 20.0 3.0
50000 20.0 3.0
#

---

Finally, is the stage discharge curve file an alternative to the column SL?

Thank you again for you attention :)

Hi,

and to complete riadh's answer,
the stage discharge curve file is NOT an alternative to SL

SL means free surface (I guess it comes from the french "surface libre"). A stage-discharge curve is probably not suitable for yur outlet in the sea...

As your simulation is 300 time steps x 5s = 1500s,
at each step an inflow of 20m3/s will be imposed at liquid boundary 2 and a free surface = 3m at liquid boundary 1

Hello

the run stops probably because time step is big (5s) try with smaller one (1s or 2s).
there are lots of useless keywords, remove the following :
steering file = ...
debugger = ..

do you really need turbulence, if not remove TURBULENCE MODEL
do you really need control section?, if not remove SECTIONS INPUT FILE ='control_section.txt' and SECTIONS OUTPUT FILE ='output3.txt'
the accuracy of the solver is not sufficient, put it at 10-4 or 10-5

I hope that this helps
Riadh