Good thinking, Dale!
Regards, Neil Tucson, AZ
-----Original Message-----
From: Dale.Clay@mdhelicopters.com [mailto:Dale.Clay@mdhelicopters.com]
Sent: Friday, October 24, 2003 9:19 AM
To: saltrat@pro-blend.com; john@engr.wisc.edu; land-speed@autox.team.net
Subject: RE: p-51(Not really LSR but might apply)
Has anyone considered using surface cooling? NO additional aero drag ..
Dale C.
Subject: Re: p-51(Not really LSR but might apply)
HHMMMM....I wonder how the analysis compares to actual
performance between
400 and 500. John do you know? I don't think we got much, if
any thrust
from the doghouse (I may be wrong) but did realize gains as
I mentioned
previously from closing the door. This avoided taking air
onboard through a
duct which is an aerodynamic no-no in most cases due to duct
drag numbers
being higher than external (skin) drag. I think that if duct
drag is added
to external skin drag you at least double the total drag of
the duct skin
area. Any radiators inside the duct add more drag due to
fins, slowing the
air down and the relatively small temperature change of air
passing through
the duct would make precious little thrust.
I have some performance data on the airplane and a few
results from changes
made while I was working on it but not much with it in it's
stock form. We
had clipped wings and a modified canopy. The rest of the
airplane was
aerodynamically stock. Some propeller blade changes really
helped over 400.
Last I heard of the really good blades is that they were
originally used on
an experimental Northrop night fighter and Gary Levitz had
them. That was
many years ago. Anyway you have got me looking at some of
the tricks we
employed....thanks.
Skip
|