Re: [Paddlewise] Greenland paddles

Yes, there is lift. However, Nick is saying that the lift contribution
to forward motion is very small, which seems to be a valid claim.

The effects of the lift are dramatic when doing rolls, braces, and sculls,
but even though one can feel the lift also when paddling forward, 
that lift is much smaller than when doing rolls.

There has to be something else going on that makes the Greenland
stroke so powerful, as it is hard to believe that such a thin stick
would move you forward at all.

Maybe the combination of foil shape and narraw blade creates a fast
eddy around the paddle that provides the mass*velociy factor necessary
to provide a good momment of inertia to the kayak (m*v = M*v')

Whatever it is, the Greenland paddle works incredibly well, but
the real reason why remains a mystery.

If there is ever some serious scientific study aimed at improving or
refining Greenland paddles, then we might know.

- Julio

K in response to Nick wrote:

> > This concept has been brought up before. The idea that the greenland paddle
> > uses lift to propel the boat just makes no physical sense. The paddle just
> > does not move far enough laterally through the water to provide significant
> > lift. It, like most paddles is being used primarily as a parachute, not a
> > wing.
> > 
> 
> This is simply not true. I have a degree in physics as well, and it makes
> perfect physical sense to me. The greenland paddle in its three main
> varieties of strokes has a high lateral component of velocity at the ends
> of the paddle. With the proper angle of attack and with a well constructed
> foil shape, there is laminar flow across the paddle, and lift is generated
> in the opposite direction of which the paddle is being pulled. Learning
> how to make the lateral velocity of the paddle fast enough to generate
> lift takes a fair bit of practice -- I can do it reliably in two of the
> three kinds of strokes. Come to Seattle and I'll show you. Greenland
> paddles generate lift.
> 
> 

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