RE: [Paddlewise] Paddle cross sections

From: Peter Treby <ptreby_at_ozemail.com.au>
Date: Fri, 7 Dec 2007 17:05:26 +1100
Amateur conjecture: An asymmetric airfoil produces lift away from the higher
side of the foil when moved through a fluid. This is due to the relative low
pressure on that side. A symmetric blade at an angle of attack produces lift
away from the back side of the blade due to relative low pressure on that
side of the blade, because of turbulance.

"... if the paddle is flat on one side and slightly curved, edge-to-edge,
(symetric edge-to-edge, uniform curve) on the powerface"
Does anyone make Greenland paddles asymmetric (one side flattish, other more
curved)? Did Greenlanders do that? Some Aleut paddles are flat one side and
ridged the other, was that for a foil effect? Do we know which side of such
an Aleut paddle was the power face?

"...it is the nature of efficiency that it feels harder."
A stroke that feels harder can also be less efficient. E.g.(as you know), a
stroke which carries too far past the paddlers body can feel hard because
the blade "lifts water" at the end. Putting that the other way, a more
efficient stroke feels easier, for the same boat speed. Hmmm, perhaps I've
just defined efficiency by the definition of efficiency!

Pleasing that this thread has created the "Greenland Horizontal Wing
Rudder". That will add to paddling enjoyment next time the GP is used.
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Received on Thu Dec 06 2007 - 22:05:40 PST

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