open TELEMAC-MASCARET The mathematically superior suite of solvers

Hello

To prescribe a flowrate at a boundary, you have to be sure that this latter is wet i.e. water depth is not zero.
If there is no specific hard constraint to start with zero depth, you can change your intitial condition to "constant depth" or "constant elevation". There is a more elegant way to start with more "physical" initial conditions by the use of condin.f surboutine.
If I remember well, your domain is not too large, so you can start with constant elevation and you should reach a physical state very quickly.

I hope that this is helpful

Kind regards
Riadh

Thank you Riadh!

I followed your advice that using the constant elevation and the condin.f subroutine, but I still can't get a result with the liquid boundaries file.

I want to know whether should I modify the cli file when using the constant elevation as the initial condition. What should the inflow use, 455 or 566?

Best Regards,
MR

Thank you Riadh!

I followed your advice that using the constant elevation and the condin.f subroutine, but I still can't get a result with the liquid boundaries file.

I want to know whether should I modify the cli file when using the constant elevation as the initial condition. What should the inflow use, 455 or 566?

When I use 566, I can get a result without the liquid boundaries file. But, when I added the liquid boundaries file, the result is :
ITERATION 0 TIME: 0.0000 S
THE LIQUID BOUNDARIES FILE CONTAINS
25 LINES WITH:
Q(1) SL(2) Q(3) Q(4) Q(5) Q(6)
USING STREAMLINE VERSION 6.3 FOR CHARACTERISTICS

THE STEADY STATE HAS BEEN REACHED

STEADY STATE REACHED, TELEMAC-2D IS STOPPED

CORRECT END OF RUN



When I use 455, I can't even get a result.
ITERATION 0 TIME: 0.0000 S
DEBIMP : PROBLEM ON BOUNDARY NUMBER 1
GIVE A VELOCITY PROFILE
IN THE BOUNDARY CONDITIONS FILE
OR CHECK THE WATER DEPTHS

PLANTE: PROGRAM STOPPED AFTER AN ERROR


Should I regenerate the geometry file and the boundaries condition file? Or the problem has other reasons?


Best Regards,
MR

Dear Riadh,

I'v found that I made a mistake when I use the command initial condition=constant elevation, I should set a initial elevation for the constant elevation. And I added it, now I can run it, but still have problems with adding the liquid boundaries file. the result is:
ITERATION 500 TIME: 1 H 6 MIN 40.0000 S ( 4000.0000 S)
LIQUID BOUNDARY: SL(2) = 0.84666666666666668
LIQUID BOUNDARY: Q(1) = 1.8398322413333335E-002
LIQUID BOUNDARY: Q(1) = 1.8029349666666666E-002
LIQUID BOUNDARY: Q(3) = 0.38839412978666665
LIQUID BOUNDARY: Q(3) = 0.38322851133333335
LIQUID BOUNDARY: Q(4) = 0.22313626825333333
LIQUID BOUNDARY: Q(4) = 0.22033542966666669
LIQUID BOUNDARY: Q(5) = 0.12033542948000001
LIQUID BOUNDARY: Q(5) = 0.11740041900000001
LIQUID BOUNDARY: Q(6) = 0.16843270453333334
LIQUID BOUNDARY: Q(6) = 0.16503144666666669

---

ADVECTION STEP

---

DIFFUSION-PROPAGATION STEP
GRACJG (BIEF) : EXCEEDING MAXIMUM ITERATIONS: 100 RELATIVE PRECISION: 0.2852702E-01

---

BALANCE OF WATER VOLUME
VOLUME IN THE DOMAIN : 628.2585 M3
FLUX BOUNDARY 1: 0.1821384E-01 M3/S ( >0 : ENTERING <0 : EXITING )
FLUX BOUNDARY 2: -0.000000 M3/S ( >0 : ENTERING <0 : EXITING )
FLUX BOUNDARY 3: 0.3858113 M3/S ( >0 : ENTERING <0 : EXITING )
FLUX BOUNDARY 4: 0.2217358 M3/S ( >0 : ENTERING <0 : EXITING )
FLUX BOUNDARY 5: 0.1188679 M3/S ( >0 : ENTERING <0 : EXITING )
FLUX BOUNDARY 6: 0.1667860 M3/S ( >0 : ENTERING <0 : EXITING )
RELATIVE ERROR IN VOLUME AT T = 4000. S : 0.1911993E-01
GRACJG (BIEF) : EXCEEDING MAXIMUM ITERATIONS: 100 RELATIVE PRECISION: 0.1411735E-01
GRACJG (BIEF) : EXCEEDING MAXIMUM ITERATIONS: 100 RELATIVE PRECISION: 0.1556387E-01
GRACJG (BIEF) : EXCEEDING MAXIMUM ITERATIONS: 100 RELATIVE PRECISION: 0.1758836E-01
GRACJG (BIEF) : EXCEEDING MAXIMUM ITERATIONS: 100 RELATIVE PRECISION: 0.2022909E-01
GRACJG (BIEF) : EXCEEDING MAXIMUM ITERATIONS: 100 RELATIVE PRECISION: 0.1793488E-01
GRACJG (BIEF) : EXCEEDING MAXIMUM ITERATIONS: 100 RELATIVE PRECISION: 0.1620564E-01
GRACJG (BIEF) : EXCEEDING MAXIMUM ITERATIONS: 100 RELATIVE PRECISION: 0.1600693E-01
GRACJG (BIEF) : EXCEEDING MAXIMUM ITERATIONS: 100 RELATIVE PRECISION: 0.1965548E-01
GRACJG (BIEF) : EXCEEDING MAXIMUM ITERATIONS: 100 RELATIVE PRECISION: 0.1107294E-01
GRACJG (BIEF) : EXCEEDING MAXIMUM ITERATIONS: 100 RELATIVE PRECISION: 0.9575210E-02
GRACJG (BIEF) : EXCEEDING MAXIMUM ITERATIONS: 100 RELATIVE PRECISION: 0.7544046E-02
GRACJG (BIEF) : EXCEEDING MAXIMUM ITERATIONS: 100 RELATIVE PRECISION: 0.4828995E-02
GRACJG (BIEF) : EXCEEDING MAXIMUM ITERATIONS: 100 RELATIVE PRECISION: 0.4867244E-02
GRACJG (BIEF) : EXCEEDING MAXIMUM ITERATIONS: 100 RELATIVE PRECISION: 0.4906606E-02
GRACJG (BIEF) : EXCEEDING MAXIMUM ITERATIONS: 100 RELATIVE PRECISION: 0.4980104E-02
GRACJG (BIEF) : EXCEEDING MAXIMUM ITERATIONS: 100 RELATIVE PRECISION: 0.5014139E-02
GRACJG (BIEF) : EXCEEDING MAXIMUM ITERATIONS: 100 RELATIVE PRECISION: 0.5505266E-02
GRACJG (BIEF) : EXCEEDING MAXIMUM ITERATIONS: 100 RELATIVE PRECISION: 0.4597419E-02
GRACJG (BIEF) : EXCEEDING MAXIMUM ITERATIONS: 100 RELATIVE PRECISION: 0.6185831E-02
GRACJG (BIEF) : EXCEEDING MAXIMUM ITERATIONS: 100 RELATIVE PRECISION: 0.5594771E-02
GRACJG (BIEF) : EXCEEDING MAXIMUM ITERATIONS: 100 RELATIVE PRECISION: 0.8235903E-02
GRACJG (BIEF) : EXCEEDING MAXIMUM ITERATIONS: 100 RELATIVE PRECISION: 0.7882592E-02
GRACJG (BIEF) : EXCEEDING MAXIMUM ITERATIONS: 100 RELATIVE PRECISION: 0.1032509E-01
GRACJG (BIEF) : EXCEEDING MAXIMUM ITERATIONS: 100 RELATIVE PRECISION: 0.1035156E-01
GRACJG (BIEF) : EXCEEDING MAXIMUM ITERATIONS: 100 RELATIVE PRECISION: 0.7910501E-02
GRACJG (BIEF) : EXCEEDING MAXIMUM ITERATIONS: 100 RELATIVE PRECISION: 0.5974180E-02
GRACJG (BIEF) : EXCEEDING MAXIMUM ITERATIONS: 100 RELATIVE PRECISION: 0.1033851E-01
GRACJG (BIEF) : EXCEEDING MAXIMUM ITERATIONS: 100 RELATIVE PRECISION: 0.1378252E-01
GRACJG (BIEF) : EXCEEDING MAXIMUM ITERATIONS: 100 RELATIVE PRECISION: 0.1403844E-01
GRACJG (BIEF) : EXCEEDING MAXIMUM ITERATIONS: 100 RELATIVE PRECISION: 0.9603762E-02
GRACJG (BIEF) : EXCEEDING MAXIMUM ITERATIONS: 100 RELATIVE PRECISION: 0.1304354E-01
GRACJG (BIEF) : EXCEEDING MAXIMUM ITERATIONS: 100 RELATIVE PRECISION: 0.6509141E-02
GRACJG (BIEF) : EXCEEDING MAXIMUM ITERATIONS: 100 RELATIVE PRECISION: 0.7830182E-02
GRACJG (BIEF) : EXCEEDING MAXIMUM ITERATIONS: 100 RELATIVE PRECISION: 0.8953271E-02
GRACJG (BIEF) : EXCEEDING MAXIMUM ITERATIONS: 100 RELATIVE PRECISION: 0.1034571E-01
GRACJG (BIEF) : EXCEEDING MAXIMUM ITERATIONS: 100 RELATIVE PRECISION: 0.5983862E-02
GRACJG (BIEF) : EXCEEDING MAXIMUM ITERATIONS: 100 RELATIVE PRECISION: 0.4092209E-02
GRACJG (BIEF) : EXCEEDING MAXIMUM ITERATIONS: 100 RELATIVE PRECISION: 0.2903471E-02
GRACJG (BIEF) : EXCEEDING MAXIMUM ITERATIONS: 100 RELATIVE PRECISION: 0.3676535E-02
GRACJG (BIEF) : EXCEEDING MAXIMUM ITERATIONS: 100 RELATIVE PRECISION: 0.6602622E-02
GRACJG (BIEF) : EXCEEDING MAXIMUM ITERATIONS: 100 RELATIVE PRECISION: 0.1660801E-01
DEBIMP : PROBLEM ON BOUNDARY NUMBER 6
GIVE A VELOCITY PROFILE
IN THE BOUNDARY CONDITIONS FILE
OR CHECK THE WATER DEPTHS

PLANTE: PROGRAM STOPPED AFTER AN ERROR

can you help me to check?

I added the steering file, the condin.f, boundaries condition file and the liquid boundaries file FYI. and the geometry file you can download in the former replies.

Best Regards,
MR

here is the steering file and liquid boundaries file

Hello

I see that you have problem with the solver convergence, this is probably because you use a very big time step, i.e. 8s.
You need, thus, to reduce time step, for example to 2s and see if this warning message desappears, otherwise, reduce it further to 1s,or 0.5s etc.

With my best regards
Riadh

Riadh,

Thank you so much!
Nice Day!

MR

Hi Riadh,
I am sorry to trouble you again.
I have encountered the same problem in another sites, which is a little bit different from the former one.
the upstream elevation is about 111m and down stream elevation is about 104m,so when I use the initial condition = constant elevation, the initial elevation=111m.
and I added the condin.f in the cas file.
but this time, when I am trying to add the liquid boundaries file to the cas file, the result comes out like this:
DEBIMP : PROBLEM ON BOUNDARY NUMBER 2
GIVE A VELOCITY PROFILE
IN THE BOUNDARY CONDITIONS FILE
OR CHECK THE WATER DEPTHS

Would you please give me some advice on this situation?
I am looking forward to your reply!

Best Regards,
MR

Hello

This warning is given by Telemac when there is a liquid boundary which is getting dry or/and when there is a supercritical regime appearing in that area.
Therefore you need to verify if you are drying the area around the liquid boundary and in that case, check why does it happen (high flowrate (negative) gradient in the liquid boundary file, very steep bathymetry gradient, supercritical regime appearing, very big time step, etc. )
In the case of supercritical regime, an additional boundary condition is necessary to impose correctly the flow conditions.
Finally, this warning is generally not blocking for the computation and it appears when there is strong variations in transient flows. After a "stabilisation" period, the flow will be much less transient and this warning will probably desappear.

With my best regards

Riadh ATA

Dear Riadh,
Thank you very much for your reply!
But I still not find the reason why it didn't work well.
Would you please kindly help me to check the data via the following link?
drive.google.com/folderview?id=0BwvRlDkE...YN2YxeFE&usp=sharing

Best Regards,
MR