"Capt. NealŪ" wrote in message
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"Gary L. Burnore" wrote in message
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On Sun, 05 Jun 2005 21:59:29 GMT, "Roger Long"
top posted like a ****ing moron and wrote:
It has been repeatedly demonstrated that airplanes glide significantly
farther (up to 20%) when the nose is raised to slow them down enough to
stop the prop and best glide speed is then resumed. I can't see any
reason why this wouldn't be true of boat propellers as well.
Because aircraft are entirely in the air an boats are partially in
water. Airplane props are feathered, boat props aren't.
I used to fly an ultralight aircraft - a Rotec Rally 2B. It had a
two-bladed wood prop that was driven by a Kohler air-cooled
432cc two-stroke engine via a centrifugal clutch and belt.
I could climb to about two or three thousand feet and shut off
the motor and the propeller would free-wheel because of the centrifugal
clutch being disengage. The glide ratio was terrible
with the prop free wheeling - one could feel the drag it caused.
I put a brake on the clutch hub and stopped the prop from
free-wheeling and the glide ration increased dramatically.
The same extra drag is evident on a boat propeller that free-wheels.
It's as if the two blades turn into a fixed disk.
CN
You guys need to get a room.
John Cairns
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