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Old Nov 11, 2011, 10:08 AM
JC Spohr is offline
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3D Hack
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United States, IL, Glen Carbon
Joined Jul 2010
2,085 Posts
Quote:
Originally Posted by Aeroplayin View Post
Also, the mechanical formula tells us the amount of power in Watts it takes to turn a 15x8 propeller with a 1.08 pK 5,760 RPMs, which was the APC's RPM reading at half-throttle from Lee's data. So it takes 338 Watts to do this, while it takes 1,100 more Watts to go from 5,760 RPMs to 8,560. That's 338W to produce the first 5,760 RPMs and 1,100W to generate the remaining 2800 RPMs.

So for the APC prop, that's 17 RPMs per Watt for the first half of the throttle curve and 2.5 RPMs per Watt for part-2. When I have some time, I'll run the numbers for the rest of the prop samples from Lee's data so we can compare to the reproduced data that should be coming soon.
This is a darned interesting subject and it just keeps getting more and more interesting.

Thanks again for the effort and sharing.

JC

ps - I hope Tom is going easy on your test (and personal) budget.
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Last edited by JC Spohr; Nov 11, 2011 at 02:49 PM. Reason: I type faster than I proof read
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