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Hi
We found the same thing on Q2 vs Q235 the larger coarse
prop had a lower drag than the small fine pitch. The glide ratio with the
Q235 is about 13:1 compared to a brick. We have tried a constant
speed on the Q2 and I was amazed at how much drag you could get when set max
fine pitch.
P factor I suspect that the apparent surprise is to
do with the reverse rotation of you former set up cancelling out some of the P
factor (engine one way prop other way) so you mostly only have air flow related
P factor. Now you got engine+prop rotation+air flow to contend
with. All good fun!
Clive Clapham
Progress on direct drive 13B painfully slow.
----- Original Message -----
Sent: Monday, March 22, 2004 4:25
AM
Subject: [FlyRotary] Re: Data? Was :
Renesis & RD-1C drive testing
>
> Most unexpected finding so far is the radically
improved glide at idle
> setting. Have no clue why. Would
have expected worse instead of better.
>
>
Tracy
Don't you have radically increased pitch in the prop? That will
do it.
Charlie
Yep, 88" pitch. Guess I figured even at that blade angle air flow
would be fully stalled past the prop and the disk area being larger
would cause more drag. I was obviously wrong.
Also noticed that having a direct MPG readout makes finding the most
efficient descent angle & throttle setting easy to find. It's a
lot different than on the other redrive/prop.
Tracy
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