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On Wed, 21 Apr 2004 21:11:20 -0400, Chad Robinson wrote
Perry, if you could share the formulae you're using I'd be happy to make a spreadsheet calculator for this. So far I've found very complex prop calculators but nothing straightforward.
By the way, why are you asking desired cruise speed? 400 knots! =)
Do your calculations focus on pitch/length or do they also provide some means of calculating dimensions at various stations from the hub, so forming templates can be made?
Regards,
Chad
It's not simple enough to put in a spreadsheet.
I think Al Wick uses the Bates Prop program, I don't know anything about that program and I don't know why he couldn't develop numbers for Bulent.
The programs I use are all in the book "Modern Propeller and Duct Design" by Martin Hollman. They are BASIC programs that I have improved on and now run as visual basic macros. They have proven to be very good at predicting reality.
Data entry is actual blade parameters along the length of the blade, so the process is "trial-and-error". Enter a blade design and examine the output to see what the performance is. The Bates program might be the opposite, enter performance numbers and it spits out a blade design (?).
I want to know desired cruise speed and cruise RPM as a first estimate for pitch. Actual cruise speed is limited by thrust produced and the drag of the airplane, so equivalent flat plate area of the airplane is also a desirable thing to know.
Perry
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