Subject: Simple cheap cooling system.
From: ACRE
Date: 9/6/2003, 11:45 PM


Brian,
There you go mate, your doing everything Paul's suggested and now he
changed
his mind - completely !!
George (down under)


I am never satisfied with the status quo :)

BTW What Brian is proposing is fundamentally
the same as the new idea except the rad can be even larger if
necessary.
A rad that large will probably be under the engine and will probably
dump
the air straight down out of the bottom of the cowl. That is the only
way
it is going to work well.

I find it kind of strange people are jumping all over me for the new
idea
when they accept this arrangement without question. IMHO kind of
strange
psychology.
A little like a shark feeding frenzy :)

Paul Lamar


Paul,
 Forgive me mate I'm a bit of a joker - I like a laugh now and again.
I understand your a more serious person!

What I was alluding to is -we that are ignorant of all that is involved
in
cooling (I speak for myself here) have just, after many years, just got
used
to a logical concept and you just turned it on it's head.

Not true it is only a minor modification and improvement.


My understanding was that to reduce drag and eliminate the boundary
layer a
smaller P51 type opening was necessary - we needed to slow down the air,
compress it, turn it 70 (approx) degrees (the slow turbulent air
absorbed
the heat better) and shove it out the back with louvers controlling the
process.

The opening is the same size. The diffuser is the wedge over the rad.

Instead of taking too much air in and controlling the flow with
louvers we can open and close the inlet by raising and lowering the
front of the rad. You can still use lovers if you wish. There is
nothing about this idea that prevents that.

Now were going full opening (however the slope of the radiator would
reduce
the frontal area to that similar to a scoop opening) ie 30%, and were
going
for a straight through radiator with the associated speed of air and
ignoring the boundary layer.

We don't have to ignore the boundary layer. If you want to provide
a boundary layer bypass all you need do is provide a flat top plate
for the rad and space the whole works down several inches below
the fuselage.

Hey mate if it works as well, I will be the first to say
congratulations,
your a genius. However my poor brain can't move from one concept to
another
that fast without some confusion. I guessing from the discussions - some
other builders may feel the same way.

No criticism of the concept intended.

George (down under)


I did not think of this idea. Several airplanes are flying with it
successfully. I merely noticed it at OSH and was amazed at it's simplicity
elegance and beauty. Peter Cowan on here has it on his Rans S7 float
plane.


Paul Lamar


For those who are concerned about the cosmetics and or possible damage from
rocks with this method, just mold a simple external (pretty) duct from the
rad opening forward toward the front strut.
I see no real difference between this "new" design and the "old" design
aside from allowing a larger rad.
And simpler!
Possibly a slightly larger frontal area, but if you raise the rad during
cruise, and allow a good portion of the airflow to bypass the rad, it is
minimal.
The cowl could be more streamlined as well since the rad inlet is no longer
there..
I like it for a tractor application.

Ron Freier
Vision 2+2
13B Turbo (Several years to go!.)

 
The AirCraft Rotary Engine NewsLetter.  Powered by Linux.
ACRE NL web site. http://home.earthlink.net/~rotaryeng/            
Copyright 1998-2003 All world wide rights reserved.