From: "Perry Mick" <pjmick@mail.viclink.com>
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
Subject: Re: [FlyRotary] Re: Performance Props
Date: Wed, 21 Apr 2004 17:22:22 -0800
Message-Id: <20040422011320.M30689@mail.viclink.com>
In-Reply-To: <list-3183469@logan.com>
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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