Hi all, I'm new to OpenFoam
 

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

Setting the two reservoirs to
 

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?