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.

Paul,
I found a couple of things in the program that you may want to take a
look at:

In the "ThrustInc" and "DragInc" calculations I think the "CordVel"
needs to be changed back to ft/sec by adding the factor 88/60 so that
CordVel becomes (CordVel*88/60).

Also, in the "angle2Deg" calculation, shouldn't that be related to the
actual pitch of that segment, which would include blade twist?   It is
not necessarily  "90 - angleDeg" is it?

Aubrey

Thanks Aubrey. I'll take a look. Still a work in progress.

Paul Lamar ...No rotor no motor.

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