prop formula

[George Kennie]

A little addendum to the prop formula that was on the list a couple
of days ago.It was purported to be from Mike Nauman and went like
this:
No. of blades, X pitch squared, X diameter cubed.
I tried the formula and felt that it didn't work. Then I tried it
again today and felt that it corresponded to my experience. Then I
tried it in a different range and it came up failing again. So I
tried to simplify it a little and due to the fact that I find that
the diameter is the most crucial component of the formula I decided
to leave all else alone and just modify the diameter. So what I
ended up with was:
Number of blades, X pitch, times diameter squared.     Applying this
formula in several ranges seems to work for me. See what you think.


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