Re: REFLECTOR: NACA scoop

[Jeff Barnes <jcbarnes@ibm.net>]

Natural convection isn't that effective on ground (not moving) cuz our
cowling exits aren't higher than the plenum.  The suck from the prop or
what little ram air you can get during taxi is your ground cooling. 
Another problem with the armpits & updraft is the cooling air is making
more turns hence requiring, theoretically, larger (thus more draggy)
scoops than a system with fewer turns.

Besides reduced drag (we hope, we hope), another benefit of the
downdraft as seen on SUV is that at after shut off, hot air goes back up
& out the scoops.  As far as ground operations go, I think your getting
about the same: suck from prop + whatever ram from motion.  As to
whether it works, ask Charles Ufres (Sorry about any mispelling Chuck)
who reports his downdraft cools very well.

--Jeff Barnes

Clint Spooner wrote:
> 
> Regarding the updraft cooling - Is there some inherent problem with
> updraft cooling? It would seem that natural convective airflow would
> aid updraft cooling during ground operations.
>