Guy's,
I don't know a lot about this but I'll dare to comment anyway.
Many planes were built with a scoop way back on the fuse.
The German military thought the little scoop back on the fuse was
too risky so they had it moved to the front.  This caused the prop to
approach the inlet, pushing air into the rad, and as it passed by it
would pull the air back out again causing overheating problems.
North American solved this by moving the scoop back to where
it is now. The little scoops back on the fuse were still having
problems and someone came up with the notion that the boundry
layer was deflecting off the fuse and into the scoop, causing
an air dam. N.A.s answer to this was to pull the rad inlet away
from the fuse and the boundry layer. It seems to have worked.
Hope I'm not too far off here.
Larry Mac Donald
Rochester N.Y.
do not archive


On Wed, 30 Jun 2004 07:52:21 -0400 "Steve Brooks" <steve@tsisp.com>
writes:
> Ed,
> I would like to have more information on the reason for keeping the
> boundary layer air out.  My current scoop is open, and lets in both.
If the
> boundary layer air needs to be excluded, then my next scoop will have
to be
> like the P51 scoop which does exclude it.  I never really understood
why.
>  Looks like I may have to have another look at Bulents' scoop.  His
> is made like the P51.
>
> Steve