Paul Lipps had this to say about single blade props:
> Single-Blade Myth
> One of the myths that has been propagated in the aviation community,
> to the point that it=92s almost become gospel, is that the most
> efficient prop is a single-blade and that all props with higher
> numbers of blades fall further and further short of this paragon.
> Did you ever consider that a single-blade prop, developing thrust on
> only one side of the plane as it revolves, would cause the engine to
> cone violently in its mounts as it is twisted by the prop?
>
> Airbus Military=92s latest turboprop transport, the A400M, has eight-
> blade props! The Boeing MD-900 helicopter has a five-blade rotor. A
> popular regional turboprop airliner has a five-blade prop. Hasn=92t
> anybody filled these aircraft manufacturers in on the errors of
> their ways? In a past issue of a popular aviation magazine, the
> author of an article on props uttered the same fallacy. He
> maintained that multiple blades interfere with each other.
>
> When I pointed out to him that at 200 mph and 2800 rpm the blades on
> my three-blade prop follow three distinct helical paths through the
> air, and each blade is 25 inches ahead of the previous blade at the
> same point of rotation, he rather lamely explained that in static
> conditions interference occurs. Static? Who uses static thrust?
> Airplanes are meant to fly, not pull tree stumps!
>
http://www.eaa.org/experimenter/articles/2009-02_elippse.asp
Fred
On Apr 19, 2010, at 3:23 PM, GRAHAM SINGLETON wrote:
> Think about the one blade for a moment. It produces thrust one side
> of the airplane only, left, top, right then bottom. And that doesn't
> include the asymmetric effect of angle of attack.The airframe will
> oscillate in a corkscrew fashion, what a horrible prospect I can
> almost feel my teeth rattling at the thought of it!
> From: Raimo Toivio <raimo.toivio@rwm.fi>
>
> Well Graham - Germans have done many "impossible" things during
> centuries...
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