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TOPIC: Conditions limites

Conditions limites 14 years 7 months ago #147

  • Yanis
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Bonjour.

Lorsque j'impose une vitesse variable en condition limite, le calcul se fait sans prendre en compte la courbe de V(t) introduite dans cas.liq, et la vitesse est, par défaut 0. Par contre, les Surfaces Libres variables sont prises en compte.

Je ne comprend pas, j'ai vérifié que le fichier cas.liq est bien écrit.

Est ce que quelqu'un a une petite idée ?!

Merci d'avance..
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Re:Conditions limites 14 years 7 months ago #148

  • c.coulet
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Bonjour,

Vérifiez que dans le fichier des paramètres le mot clés VITESSES IMPOSEES est bien précisé. C'est ce mot clé qui permet "d'activer" la variation de vitesses au niveau conditions limites et malgré la présence de ce mot clé, les vitesses imposées seront bien issues du fichier cas.liq

Cordialement,
Christophe
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Re:Conditions limites 14 years 7 months ago #150

  • Yanis
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Bonjour et merci pour votre réponse,

Le mot clef est activé, et sa valeur est (par défaut) 0;0 . Lorsque je donne une valeur de vitesse fixe, cette valeur apparait, et le calcul la prend en compte. Mais lorsque je bascule au mode "variable en temps", le calcul se fait avec la valeur de la vitesse fixe imposée précédemment..
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Re:Conditions limites 14 years 7 months ago #152

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Je pense qu'il y a un problème au niveau de FUDAA car normalement dans le fichier des frontières liquides, on doit indiquer les composantes de la vitesses U(n°frontière liquide) V(n°frontière liquide) et non Vit(t) (cf manuel d'utilisation telemac).
Vous pouvez directement ouvrir votre fichier cas.liq et le modifier manuellement. Attention à ne pas insérer de tabulation dans le fichier au moment de sa modification.
Christophe
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Re:Conditions limites 13 years 1 month ago #2708

  • pilou1253
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Hello,

I have a dam break model with the following BC:
1/ upstream : hydrograph (cas.liq)
2/ downstream : imposed water surface

Steering file parameters :
COTE INITIALE = 2.3
PROFIL DES VITESSES = 3;1
COTES IMPOSEES = 0;2.3

I have defined the speed profile for the 1/ BC using fudaa, and BC file has been correctly modified (UBOR).

When running telemac, i have the following error msg :
"Q(1)
DEBIMP : probleme avec la frontiere 1, donner un profil de vitesse dans le fichier de CL ou vérifier les hauteurs d'eau"

I tried to add water height information using fudaa on initial conditions (creates a condInit.ser file), but it does not help.
I also tried to change the COTE IMPOSEES value from 0 to 150, but it did not help neither.

Can someone explain me what i missed ? Do i have to create a SL condition in the cas.liq file for the 1/ boundary ?

Thank you in advance !
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Re:Conditions limites 13 years 1 month ago #2711

  • c.coulet
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Hi
You have to check the water heigh on the upstream boundary. If it occurs at the first time step, that means your initial condition is dry at the upstream boundary
If this message occurs during the computation that could also means that your upstream boundary is torential and the you should also impose a water level.
Hope this helps
Christophe
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Re:Conditions limites 13 years 1 month ago #2723

  • pilou1253
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Hi,

I have this msg at the first time step, t=0s.
I used fudaa to modify the IC with water surface = 2,3 m everywhere execpt on the points located on and nearby my upstream BC, where i set a logical height.
I then have a initCond.ser file, and use the resultat file procedure.
I removed the "COTE INITIALE = 2,3" from the steering file.

When launching the calculation with this setting, i have the same problem.
Before the first time step, telemac is reading my IC file and states:
"RESCUE: fichier de resultats du calcul precedent sans la vitesse U, on la prend nulle
RESCUE: fichier de resultats du calcul precedent sans la vitesse V, on la prend nulle
RESCUE: hauteur d'eau calculee avec le fond et la surface libre"

I thought the problem may be that my IC file does not have U speed information, which is non coherent with my speed profile defined on my upstream boundary. But i don't know how can i do to define it...

Do you have an idea ?
Thx
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Re:Conditions limites 13 years 1 month ago #2728

  • c.coulet
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Hi
did you check if it works with the velocity profile 1?
For me if this problem occurs at the first time step this is because the water height on the imposed discharge boundary is equal to 0 so Telemac couldn't compute the velocity in order to impose the asked dicharge.

Another possibility is to join your files in order to allow us to check your model

Hope this helps
Christophe
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Re:Conditions limites 13 years 1 month ago #2731

  • pilou1253
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Hi,

No, it does not work neither this way.
I let you check with the files.

Thank you very much !
PL

File Attachment:

File Name: pilou1253.zip
File Size: 932 KB
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Re:Conditions limites 13 years 1 month ago #2733

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Hi
This is your initial condition file which is wrong
With fudaa, in the initial condition layer, on the CI nodes, i just made a right click and select "cancel the negative water height'and the computation start well.
Here is the condinit.ser file i generated

File Attachment:

File Name: condInit.zip
File Size: 599 KB


regards
Christophe
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