"Keith Willshaw" wrote in message
...

"Gord Beaman" wrote in message
...
"Dudley Henriques" wrote:


"Are you trying to tell me that the
rotational (energy) of a propeller is
the same at 15 inches as it is at 61?"



If he was he was right, the rotational energy
is simply a product of angular velocity and mass
and is the same in coarse pitch, fine pitch or a vacuum.

The power being delivered is a different matter of course
and depends on factors such as propellor pitch, air
density and of course angular velocity.

Keith

The above is absolutely correct......... BUT.........Please do a google
search for (p51 engine seizure "dudley henriques") and read the thread
carefully, especially from the point where Gordo enters it under me. I
believe it will be instantly apparent that the reason for this
misunderstanding is obvious, and it's probably my fault. I was reacting to
someone I don't particularly like and I was mincing words. If you read the
thread carefully, you will see that what I was discussing with him about
power and rpm was missing a main ingredient; that being what I was assuming
he knew, when in actuality, I had completely omitted it from anything I was
saying to him. That ingredient is the high rpm prop limiter on the governor
of the 24D50 Ham Standard used on the Mustang. If you read what I was
writing carefully, I believe you will realize that I was assuming both of
were aware of the limiter function in relation to what we were discussing. I
was wrong in assuming this.
The facts are quite simple. Both Gordo and I know it. The only problem seems
to be that he thinks it was he who "taught" me this, and that's pure fiction
I can assure you. But the fault remains with me I think. I should have made
it perfectly clear to him from the beginning about the prop governor, as I
was considering it's function in every post I made to him, but I never
actually mentioned it.
In summation, it's 101 that rpm and not power is directly related to
rotational mass/velocity/inertia with a constant speed prop....UNLESS as I
was trying to say, the power is back past the high rpm limit stop as it very
well is at idle power on the Mustang. This assumes normal aerodynamic loads
on the prop as well.
With this in play, it becomes totally correct to say that the rotational
forces in play at 15 inches on this airplane are less then they would be at
61 inches, or anywhere else for that matter within the 42 degree pitch
limits where a power change or a change in aerodynamic load would cause a
pitch change to maintain a constant set RPM on this specific prop. I'm very
sorry if what I said was misleading to Gordo. I should have discussed the
prop governor with him from the onset. The plain truth is that I was just
too ****ed off at him and just plain missed it.
Such is Usenet!! :-)
Dudley Henriques
International Fighter Pilots Fellowship
Commercial Pilot/ CFI Retired
For personal email, please replace
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