One of the questions I get asked over and over again is what
about NACA ducts for radiator air inlet? We have discussed this
many many times on here before.
Some people do not get the message. Perhaps they are deliberately
spreading false information about my position on this for personal
agenda reasons.
The NACA engineers themselves.... the people that invented the NACA
duct DO NOT RECOMMEND THEM FOR HEAT EXCHANGERS!!!! Here is a photo
copy (if you will) of the part of the original NACA duct technical
paper NACA-ACR 5i20 that so states. The complete paper is on the
web and can be downloaded from the NASA web site as a 12 meg pdf file.
Yes they might work for cooling air cooled aircraft engines because
air cooled aircraft engines have more space between the fins
and consequently less restriction to air flow. What works for air
cooled engines does not necessarily work for liquid cooled engines.
They also might work if the air is extracted from the back side of
the radiator by some mechanical means.
Paul Lamar
Pretty clearly stated. Interesting to note that by the "CONFIDENTIAL"
markings this information was apparently considered classifed information at
one time - what was the date on the doc, WW II vintage??
Ed Anderson
