Outgoing flow

[QuentinG]

Hello everyone,

Just a quick question about outgoing flow,
I want to modelize a wind tunnel and my condition is an outgoing flow, how can I manage to do that ?
Do I have to set the outlet as an inlet with a negative velocity and the inlet as a free inlet/outlet ?

Moreover the incoming flux is heated to a constant temperature, so is there a way to apply a temperature to the free inlet ?

Thank you,
Regards,

Quentin

P.S. : I am using the GUI with Windows

[Yvan Fournier]

Hello,

Yes, an inlet with a negative velocity should work as a prescribed outlet.

I'm not sure about prescribing a temperature on a free inlet/outlet. You can probably force the Dirichlet condition using low-level user functions. For a standard outlet, the GUI allows setting a prescribed value for backflow, so you may experiment that first (instead of a free inlet/outlet).

Regards,

Yvan

[QuentinG]

Thank you very much Yvan I will try that,
I have also a little question about symmetries :

Is the previous picture equivalent to the following one ? (the dotted planes are the symmetry planes)

(just to ensure that code_saturne support those two symmetric planes as it should be mathematically).

Regards,

Quentin

[Yvan Fournier]

Hello,

Yes, this should work. We have some minor precision issues with this type of symmetry, so using a rotational periodicity may be an alternative, though it is computationally more costly.

Best regards,

Yvan