Hi, fellow rotary enthusiasts....I just had to
share my rotary cooling success story. As many of you know, I have an SQ2000
canard with a belly mounted NACA duct. I decided to try adding VG's in
front of the NACA duct, as several other canardians suggested. Here is a link
showing the VG's and oil flow test. http://users.telenet.be/westlandfamily/cozy/vg/index.htm
I conducted two flights today, one without the
VG's, then one with them added. OAT was 85 degrees, and very humid. (We
were sweating just standing around).
On flight one (prior to addition
of VG's), climb temps hit 210 (water temp) and stabilized at 205 at WOT. The
highest oil temp during the flight was 190.
I landed, and we riveted on the
two aluminum VG's and I took off again. Water temp during the climb maxed
out at 190, and took much longer to reach those numbers. I raised the nose to
climb at 90 IAS (which I have not done previously) and water temp rose to 195. I
lowered the nose to climb at 100 IAS and the temps came back down to 190. After
leveling off, water temp was 180 at WOT. At approximately 3/4 throttle
(cruise) water temp was stable at 172 at 3000 AGL. After throttling back for
descent, water temps stabilized at 160 where they remained until landing
rollout. During taxi back to the hangar, temps rose back up to 182. Highest oil
temp during this flight (at any configuration) was 182.
It seems obvious that the
VG's had a positive influence on the cooling efficiency. I don't profess
to understanding exactly how the VG's trip the air into the NACA duct, or being
an expert on VG's or cooling issues. I am only reporting what worked for me. The
addition of the VG's changed my marginal cooling system into a success
story.
I should also mention that
I did not raise the front nosewheel, as I wanted to see how it would cool in the
worst possible situation, (ie landing gear motor unable to regtract the gear)
and slow climb speeds. I suspect that on the next flight, when I retract
the nosewheel and attain a higher airspeed (at the same power settings), my
temps might even come down a couple more degrees. I still need to add
wheel pants and clean up the airframe and paint it, but I have finally attained
a cooling system I am very pleased with. Paul Conner, smiling in Mobile,
AL
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