|
Hi Thomas,
I'm having a little trouble identifying whether or not
you're just playing "devil's advocate".
On the assumption that you are completely serious, it's
worth considering the following:
[1] WRT canard pushers:
A - Burt Rutan started out with a P-51 style scoop on the
Vari-EZ. IIRC the early Long-EZs also had them. He later
changed to the NACA scoop because it was more "efficient" in
some combination of cooling efficiency vs. drag.
B - Nat Puffer rescaled the NACA scoop such that it does,
in fact, provide sufficient cooling for a 180 HP Lycosaurus.
His design will go 200 MPH on less than 13 gal/hr - which
suggests a low-drag desgin.
see: http://www.cafefoundation.org/aprs/Cozy%20IV%20APR.pdf
That same scoop will also provide sufficient cooling for a
200+ HP Turbo-charged rotary even routed through multiple
heat exchangers.
[2] Sound empirical evidence ALWAYS trumps theory.
[3] Good engineering practices suggest that it is unwise to
experiment with too many things at once. In the event that
something goes awry, one may encounter considerable difficulty
in ascertaining *which* component or subsystem caused the
problem. If one wants to experiment with improved cooling
systems, it would be wise to start from a solid baseline of
a system that is _known_ to work, and change one item at a
time.
Good luck.
Dale R. ......................|......(___.......|
COZY MkIV-R13B #1254 .........|----==(___)==----|
Ch's 4, 5, 9, 16 & 23 in progress ..o/ | \o
http://www.canardzone.com/forum/showthread.php?t=1388
(Cedat Fortuna Peritis)
> From: "rijakits" <rijakits@cwpanama.net>
> Date: 2005/10/18 Tue PM 11:26:36 EDT
> To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
> Subject: [FlyRotary] Re: flyrotary_Web_Archive Re: Banishment
>
> Hi John,
> it was me, Thomas J. babling below, don't blame Monty for it!
> ----- Original Message -----
> From: John Slade
> To: Rotary motors in aircraft
> Sent: Tuesday, October 18, 2005 10:25 AM
> Subject: [FlyRotary] Re: flyrotary_Web_Archive Re: Banishment
>
>
> Hi Monty,
> ( I admit I am NOT a fan of EWP quite yet...., however stand to be corrected)
> I think Rusty used one with success in hot weather. I'm also waiting to see
> the EWP prove itself, but at least over here we're open to the possibility.
> I believe Rusty's system still kept the engine driven WP in addition to the
> EWP. Rusty?
> # NACA scoops work: Well I guess you if you make them big enough
> Let me rephrase, then. The Cozy plans NACA scoop is sufficient to cool a turbo
> rotary.
>
> of course, BUT there are better and more efficient ways to get cooling air
> in!
> I think, for a pusher, the NACA is the least draggy solution we know. I may be
> wrong.
>
> But one should take advantage of his list of resources and really dig in
> IMHO There's too much untruth and incorrect / unproven theory buried in the
> truth to make the exercise worthwhile
> I am refering to the references to the books of Kuchemann & Weber and Kays &
> London. It is "hardcore" reading but at least some of it "seems to make sense"
> even for the layman.
> Remember the inventors of the NACA-duct did recommend to NOT use it as a
> pressure-recovery intake (what we need for our our car style radiators)
> Unfortunately they "look" rather sporty, so we fall for them....
> Also even the P-51 style scoop doesn't do the best for efficiency. In one of
> the books it is mentioned somewhere (IIRC), but there were one or two testships
> with modified scoops (according to K&L I think....), which improved efficiency
> over the last production system. However that one was good enough, so the new
> one never made it to the masses and then WW2 was over and the jets on the
> doorstep.
> Once you get really into aerodynamics concerning effiecient cooling, it starts
> to hurt seeing people fight for cooling but having bad/inefficient systems.
> As mentioned before, for me the road will be the fun, not so much the
> destination, so when I get to it I will really enjoy doing lots of experiments!
> Don't hold your breath though....:)
> Now PL the pope, made me look at these books (actually only parts of it...).
> Also remember (again...) these facts do not come from grumpy old man, but are
> facts from respectable sources - he just pointed the finger in the right
> direction.
> # Earth round?? Obviously you never fell off the edge yet!! Actually it has
> the shape of a trochoid!! - bet you didn't know that!
> I did say almost. :)
> Right!
> Regards,
> John
> Saludos,
> Thomas
|
|