The Cv of 24 x 5/16" diameter holes is approximately
42.68 gpm/sqrt(psi)
Which is also the Cv of one hole of
1.531" diameter
That assumes sharp- edged orifices; no burr, no chamfer, no radius.
Oh. You want to know how to do it;
Start with hl = V^2/(2*G)
Where the V is based on an effective orifice area, in this case 0.61 times the nominal orifice area.
Compute hl for an arbitrary flow, convert hl from feet wc to psi, and compute Cv = flow / sqrt (psi)
Mike Halloran
NOT speaking for
DeAngelo Marine Exhaust Inc.
Ft. Lauderdale, FL, USA