open TELEMAC-MASCARET The mathematically superior suite of solvers

Hello,

I'm trying to run a case of canal with one source. But there is 2 problems at the simulation:

1- The flow by default start with no velocity at the source, so i put the keyword : "VELOCITIES OF THE SOURCES ALONG X = 0.02"

But shows the error:
LINE: 115 UNKNOWN COMMAND

WRONG NUMBER OF VELOCITIES OF SOURCES ALONG X

PLANTE: PROGRAM STOPPED AFTER AN ERROR
RETURNING EXIT CODE: 2

2- The problem with the temperature is the tracer became 0 at the source, but i put the tracer with 20°C:

/

---

/ TRACER
/

---

/
NUMBER OF TRACERS: 1
NAMES OF TRACERS : 'TEMPERATURE DEGRE C '
INITIAL VALUES OF TRACERS: 20.
DENSITY LAW : 1
/
COEFFICIENT FOR VERTICAL DIFFUSION OF TRACERS = 1.E-4
/
MAXIMUM NUMBER OF ITERATIONS FOR DIFFUSION OF TRACERS = 200
/
FRICTION COEFFICIENT FOR LATERAL SOLID BOUNDARIES : 60.
/
VALUE OF ATMOSPHERIC PRESSURE = 100000
/
MASS-LUMPING FOR DEPTH : 1.
MASS-LUMPING FOR VELOCITIES : 1.
MASS-LUMPING FOR DIFFUSION : 1.
/
FREE SURFACE GRADIENT COMPATIBILITY : 0.9
/

---

the file .qls is :

#
# DEBIT A L'ENTREE ET SURFACE LIBRE A LA SORTIE
#
T Q(1) SL(1) TR(1,1)
t m3/s m °C
0. 2.7 52. 22.
20. 2.7 52. 22.
100000. 2.7 52. 22.
200000. 2.7 52. 22.
300000. 2.7 52. 22.
400000. 2.7 52. 22.
#

---

Thank you in advance for the help.

Fernando

For another information i'm sending the files of the case


_____________

Hello,

Before trying to represent atmospheric heat exchanges, you should first focus on the hydrodynamics only, by turning off the waqtel coupling.
You can also setup your model in 2D first, before running it in 3D.

I'm not sure your boundaries settings are corrects for your case. You're prescribing the surface elevation on the right side of your domain (boundary n°1) and the flowrate on the left side (boundary n°2). So, in your steering file, you should have instead:
PRESCRIBED FLOWRATES : 0. ; 2.7
PRESCRIBED ELEVATIONS : 52. ; 0.
As your boundary conditions are constant in time, you needn't the liquid boundary file. Nevertheless, if you plan to use time-varying boundary forcing, the header of your liquid boundary file should be as follow:
T Q(2) SL(1)
(also remove the tab character)


Regarding your first question, you don't define any SOURCE in your steering file. So it's normal that the model complains if you ask for a velocity of the source along X...
As explained in the user documentation, a source is a punctual input/output of momentum inside your domain, not on the boundaries. To do so, you have to define in your steering file: ABSCISSAE and ORDINATES OF SOURCES (or GLOBAL NUMBERS OF SOURCE NODES) and associated WATER DISCHARGE OF SOURCES (and ELEVATIONS OF SOURCES for 3D computation). See section 5.4 of the user manual.

Regarding your second question, I understand that you're speaking of "source" for your left boundary.
You're prescribing the temperature on the right boundary of your domain (LITBOR=5), but you let it free on the left boundary (LITBOR=4). As your flow is coming in your model by the left boundary, it arrives with a 0 value. If you want to also prescribe 20°C on the left boundary, you should modify your boundary conditions file in agreement (5 4 4 ... 5) as for the right boundary (4 5 5 ... 5).
It misses the keyword "PRESCRIBED TRACERS VALUES = 20. ; 20." in your steering file or if it's time-varying, your liquid boundaries file should be:
TR(1,1) TR(2,1)

I enclose the modifications I did.










I hope it helps.

Regards,
Laurent

First of all, thank you for your help.

I already did the simulation in 2D with just the velocity, and another simulation without flow with heat exchange. The intention is to combine the two conditions.

In relation to boundaries settings, I want a free-flow input condition on the left and a water level control condition on the right.

Regarding the temperature is all right now, but regarding the velocity, at the .qsl you put the flow rate at 270m³/s, however the real flow rate is 2.7m³/s, but does not give a coherent result because the speed is much lower than in the simulation in 2D.

thank Laurent again for the help.

Regards,

Fernando

Hi Fernando,

I put 270m³/s so as to see more easily the influence of your prescribed flowrate, you just have to set it back to 2.7m³/s.

You don't have a free-flow condition on your left boundary but a prescribed flowrate (4 5 5) that is usual for this kind of case. For free flow, you can try 4 4 4, but not sure it will be stable.

If you want to compare the results with the 2D case, be careful to have the same boundary settings, particularly your surface elevation on the right boundary (48.5m according to your previous 3D steering file, instead of 52m in mine, to compare with ??m in your 2D steering file). If you have a liquid boundary file for your 2D case also, the prescribed flowrate must also be Q(2).

Regards,
Laurent

Hi Laurent,

Now i understand better the boundary condition, but now i may know the error, the size of the mesh changes when i run the simulation at telemac, for example, at the geometric file the size of the first part if 25m of width and after i run, the size is around 500m of width (20x plus then the normal) on 3D RESULT FILE , so the velocity is different because of this.

I did the simulation separated of heat exchange and the 3D velocity and i don't had this problem.

So do you already see this problem? i read at the manual some of geographic system, but doesn't make any difference.

Best regards,

Fernando

Hi Fernando,

I think it's normal as you're using the corrxy.f subroutine as user fortran with following modifications inside:
Regards,
Laurent

Thank you very much Laurent
I'm making a lot of progress because of your help.

The results of velocity and temperature are ok, but now i have a new problem. I want to put a new tracer (coliforms):

NAMES OF TRACERS : 'TEMPERATURE DEGRE C ';'COLIFORMS g/l '


but it shows a error that i don't know how to solve:
"
THE LIQUID BOUNDARIES FILE CONTAINS
6 LINES WITH:
Q(2) Q(1) SL(1) TR(1,1) TR(2,1) TR(2,2) TR(1,2)
BORD3D: MORE PRESCRIBED TRACER VALUES
ARE REQUIRED IN THE PARAMETER FILE
AT LEAST 2 MUST BE GIVEN

PLANTE: PROGRAM STOPPED AFTER AN ERROR
RETURNING EXIT CODE: 2
"
I'm seeding the files if do you want to check, but the error is at this PARAMETER FILE, and i don't know what files is this

Thank you again for the help,
Regards
Fernando

Hi Fernando,

The parameter file is the steering file.
As you have 2 tracers to prescribe at 2 liquid boundaries, you must have 4 prescribed values in your steering file.
So, you have to add 2 extra values to the keyword PRESCRIBED TRACERS VALUES, corresponding to your new tracer at the 2 boundaries.
These values will be overwritten by the one read in your liquid boundary file.
You can read the section 7.1.2 of the user manual for further details.

I hope it helps.

Regards,
Laurent

I did this and continue the same error
I only add the 2 PRESCRIBED TRACERS VALUES.

PRESCRIBED TRACERS VALUES = 20.;20.;20.;20.

Thank you for the quick reply.

To be able to run your case with v7p3r0, I had to split the line where you define the name of the tracers (damocles error at the beginning of the execution).
Then, I don't have the issue you mentioned by running your case, only an non convergence of the solver (exceeding of maximum iterations), even without any tracer. So you may check your hydrodynamic settings first (without tracer and without coupling with waqtel).
I did this test with the previous liquid boundary file and boundary conditions file I provided in the last post, and your fortran and steering files.

Regards,
Laurent