30" diam jet on 9 foot perfplate
 

Some ignorant fool agreed to have me model a system that consists of a 30" pipe expanding at 90 deg full cone angle to a 9 foot perforated plate that has 2-1/2" holes and 48% open area.

Now I've read all the docs on pressure jump and porus media, but I don't have any flow/pressure drop data on the perforated plate.

So I just modeled the actual plate (its 2" thick). Well, I tried to model it, but it looks way wrong, and although it 'converges' the flow patten keeps changing. (Even with 2nd order control)

Model is just a flow / turbulence model, constant density/viscosity.

Anyone have a clue to what kind of cell size resolution I'm going to need here?