[dannyboy]

Hi all,

I'm new to OpenFoam (and CFD) and I would just like to take the opportunity to say how impressed I am with it so far (having worked my way through all of the tutorials). :o)

However, probably because I have little experience in this, I am having difficulty in setting up a simulation to model the gas flow through a small orifice.

The approach I have taken is to have two large reservoirs connected by a small tunnel. My problem is how do I set the first reservoir to atmospheric pressure and the other to a low pressure?

I tried setting one wall of the first reservoir to 'atmosphere' (as in the interFOAM tutorial example). Is it possible to set the equivalent wall in the 2nd reservoir to a low pressure and hey presto a gas flow through the orifice will result or am I just coming at it from completely the wrong direction and need to read a heck of a lot more about CFD before even attempting this?

Hope you guys can help.

Dan

[henry]

Setting the two reservoirs to different pressures will indeed induce flow between them through the orifice. To set a non-uniform initial field look at the setGammaDamBreak utility which is part of the damBreak tutorial.

Which application are you running?