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Re: Inflight Variable Pitch Props

Subject: Re: Inflight Variable Pitch Props
From: Fred Fillinger <fillinger@ameritech.net>
Date: Thu, 8 Feb 2001 08:29:28
Dr. S. Hoerner (author, "Fluid Dynamic Drag") wouldn't quite agree,
Alan.   His formula states that velocity increases approximately with
the cube root of the increase in power.   E.g., a 27% power increase
is good for a 3% speed increase.

He says "approximately," since slicker airframes come out a bit faster
with increased power, so for the Europa you could plug a little less
than the cube root into your calculator.  Conversely, drag increases
with the square of the velocity, so drag reduction has a significant
on speed.

Cheaper than a new engine, too.

Regards,
Fred F., A063

Alan Stewart wrote:
> 
> ...and I'm fairly convinced that with just 80 horse power from the 912,
> it's power, not aerodynamic efficiency that's the primary limiting factor. 
> After
> much deliberation, I've decided that the only thing which will ever give me 
> more
> than 10 knots extra, is a much more powerful engine.
> ....


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