Perforated Duct Hole Sizing/Spacing

[jwm8778]

I am attempting to size/space perforations (holes spaced along the length) in an exposed duct to provide even air supply at each hole. I have seen another post on the subject, but do not follow exactly the procedure used. I have a 150' long 43" dia. duct with 15,000 cfm, and therefore a starting velocity of 1500 ft/min.

Can anyone direct me to a design guide or give me a small example of how to size a portion of the duct holes?

I haven't located any help in ASHRAE. Thanks so much for any help you can provide!

 

[cry22]

Consider ductsox
or see United sheetmetal, they have some pre-perforated ducts.