[BillA]

what is that ?
what equations ?
std air ?

did you read post #2 ? it is from Fantester
recommended minimum and maximum flows:

NOZZLE DIA ./ CFM @ 0.1 INCH W.G./ CFM @ 4.0 INCH W.G.
0.7 “ . . . . . . . 3.5 . . . . . . . . . . . . . . . 21.0
1.0“ . . . . . . . 6.7 . . . . . . . . . . . . . . . 42.0
1.6“ . . . . . . . 17.0 . . . . . . . . . . . . . . 110.0
2.0“ . . . . . . . 28.0 . . . . . . . . . . . . . . 172.0

max flow best @75% (3"WG)

(running at lower pressure is going to be easier on the ears)

EDIT
Ben, have you looked for a fan pumping ~200CFM @ 4+"H2O ?
now I understand why they are in enclosures