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Andrew,
I'm a bit confused with what you have provided, so
just to clarify I will ask if this is what your saying in regard to the
calculation:-
Power in HP = 0.0532 times ( diameter of prop
divided by 450) by 5 times ( rpm divided by 1,000) multiplied by 3
OR is the 5 and 3 ( to the power of).
Secondly, the 'square cross section' statement -
for the balanced bar, I assume you mean thickness, which would then mean for a
6' ( 72") bar it would be 4.8" thick - is that correct?
George ( down under) Brisbane.
Whilst
researching propellers, I came across this gem of info from www.jcpropellerdesign.com
Gustave Eiffel (1832-1923) came up with a simple solution
for measuring HP without complex apparatus, By using a balanced wood
bar instead of a propeller with a square cross section of 1/15th of the
length of the bar, you can measure the rpm and calculate the HP
available.
Power in HP = 0.0532 (diameter/450)5 (RPM/1000)3
As I need a load on the engine
when I run it I’m going to give this a go, 1350 x 90mm at 7000 rpm will give
me 191hp, that’ll do if I can get it.
--
Regards
Andrew Martin
Renesis RD1c
West Australia
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