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I am testing the model with permanent flow in a straight channel section. I attach an image with the geometric and hydraulic characteristics of the test.
The upstream boundary condition is incoming flow (Q = 20000 m3/s). That's why I use an Open boundary with prescribed Q. Downstream was imposed a fixed water height of 10 m. That's why I use an Open boundary with prescribed H.
I also add an image with the error message when running the program and the corresponding files to run it (Telema.cas y cb_QyH.liq)

I do not realize what the mistake is. Thank you!

Hi
As you have open boundaries in your model, and even you prescribed values in a text file, you should have the keywords PRESCRIBED FLOWRATES and PRESCRIBED ELEVATIONS in your steering files with two values for each even 0,0

Regards

Thank you very much for the reply. I enter the keywords PRESCRIBED FLOWRATES and PRESCRIBED ELEVATIONS in my steering files with two values for each. I enter 0,0 for both. Now the program runs.

Now I have the following problem. When I see the results in bluekenue, the water depth decreases from the initial (equal to the initial condition entered in the steering file) until approximately 2 m. I attach an image of both results, at the beginning and end of the simulation.

Therefore, the boundary conditions would not be working. There is no incoming flow equal to 20000 m3/s and there is no water height equal to 10 m imposed downstream.

Hello,

To go further we would need to see the boundary conditions file (to check that upstream is really boundary number one, the first appearing in the file). Looking at the velocity field while the domain is emptying would be also useful.

With best regards,

Jean-Michel Hervouet

Hello! I send you all the files I'm working with.


thank you very much!!

Hola,

This is it. In your boundary conditions file the first boundary appearing in the list is boundary 1, with conditions starting with 5 4 4, thus it is a boundary with prescribed depth or free surface elevation. Then comes boundary number 2, with 4 5 5, thus with prescribed discharge.

So you should have in your boundary conditions file SL(1) and Q(2).

With best regards, y que le vaya bien,

Jean-Michel Hervouet

Thank you very much for the reply!!! Was very helpful!!