open TELEMAC-MASCARET The mathematically superior suite of solvers

Hi everyone,

I am studying the singular losses in a bifurcated channel. For that I use a channel of width 1[m], discharge 50 L/s, manning 0.011, slope 0.0025.

Performing simple calculations, I am with an approximate froude of 0.82 and normal Depth 0.072 [m].

The strange thing is that at the entrance of the main channel, there are strange disturbances where the Fr> 1. In the .log file, it does not inform me about this. I've tried it and I've noticed that for very small discharge (1[L/s]) the program works well.
Does anyone have any idea of what is happening? I do not know if it will be a problem of instability or physical.

Thanks
Joaquin

result

Hello Joaquin

The right and left corner elements at the entrance are overconstrained elements. You have to swap the edge there.
At the entrance anyway, you will have disturbed flow at a certain distance from the entrance boundary. When the flow is stabilized, you will have much more nice flow feature.
if you want to figure it out, you can prescrive velocity components directly in the cli file. See example confluence in examples/telemac2d, here the flow is nicely prescribed.

with my best regards

Riadh