[mido66]

Hello everybody,

I am trying to modelise a water flow through an analyse chamber. It is a diphasic problem because this chamber is initially full of air, and because of its geometry, some air bubbles stay during the flow (it is even important that it stay).

For inlet, I have water with a given pressure (that I need to change for each calculation, my job is to determine how this pressure influence the water behaviour).
For outlet, there is a pump installed after the chamber, who suck up with a debit of 6L/h.

I am not using Ansys (Fluent) for a long time, so i need some advices concerning the boundary conditions and I have a few questions..

For boundary condition, I am using velocity inlet and pressure outlet because it is only with that that I have results yet. But I am perplexed and I am not sure that describes well my problem.

For the other questions ... :

- how I can take in account the compressibility of air ?
- what i am supposed to put in operating density ? (I currently use 998.2, the water's density, and it works I think, but I don't understand why...)
- I definitely don't understand the difference between the operating pressure, the initial gauge pressure, the pressure we put on velocity inlet and the pressure we put on pressure outlet, etc...

If anybody want to tell me to go see the fluent user's guide, I have already done that and that didn't help me (or at least not anymore ^^')

Thanks a lot for your advices, all comments will be helpfull !
And if you have any question about the configuration of my problem do not hesitate..

I am very sorry for my poor english by the way ....

[mido66]

Ok, now I just need to have an inlet pressure with a precise outlet flow rate (6L/h) ... Is there a way to do that with fluent or something else ..? (CFX perhaps ?)

I really need some help ^^'

Thank you..

[mido66]

Nop ? Nobody ?

It find that weird that we can't do such a simple thing on Fluent ...