>
> There is only one true measure of the pitch of a propeller */as
> installed on a particular airplane!/* That is the effective pitch, which
> is the amount the airplane goes forward, in inches per revolution, in
> horizontal flight. It's an easy formula: TAS, mph, times 1056 divided by
> rpm.
> Paul [Lipps]
Paul,
I'm completely lost, when it comes to props pitch and diameter, I guess it's
all math, but it seems like a black art to me.
Given the above mentioned formula, could you use that to estimate prop pitch
and diameter, from projected ( hope for) performance figures i.e. speed
(MPH) and I'm guessing the rpm is the prop RPM.
I assume once you establish a pitch and diameter, you could then fine tune
for optimum performance, given restrictions on prop ground clearance and
prop speed.
George ( down under)
It is more than that. Keep reading. Perhaps somebody on
here more swift than I could do a spread sheet version of my
QB program. The trick is to break the blade down in short
sections of wings, calculate the lift and drag and add
up the totals,
Paul Lamar ...No rotor no motor.
Hi Paul,
Here is a spreadsheet version of your program (including all
mistakes). :) This is based on the formula's in your email sent
5/11/06 at 00:48.
This spreadsheet is in Excel 97 format. StarOffice should be able to
read it OK. I can also send it in StarOffice 5 or 6 format.
Bob W.
--
http://www.bob-white.com
N93BD - Rotary Powered BD-4 (first engine start 1/7/06)
Custom Cables for your rotary installation -
http://www.roblinphoto.com/shop/
Thanks Bob. I found another bug in the latest version.
I failed to resolve the drag in the plane of prop rotation.
I am working on a fix. BTW the reason this program is so simple
compared to others is it is for one condition. One RPM.
One pitch or one coef. of lift. One diameter and one plan form.
Most programs do not take into consideration the plan form.
One twist.
Paul Lamar ...No rotor no motor.
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