Re: [Paddlewise] lift and efficiency: Definitions?

Kevin wrote:

>Ok, now lets talk about lift... but first lets talk about drag. The
>paddler is pulling backwards on the paddle (force vector points towards
>the stern). The resistance of the water (drag) on the paddle resists that
>pull (force vector points towards the bow). The drag force vector is
>slightly smaller than the paddler force vector, which is another way to
>think about efficiency. The difference in the size of the vectors
>represents the energy that is lost due to turbulence and the slippage of
>the paddle through the water. When lift is generated due to laminar flow,
>the size of the resistance vector is slightly increased because the lift
>vector points in the same direction as the drag vector. Even if further
>calculations were to show that the lift generated by Greenland paddles
>really is insignificant, efficiency is probably still increased because
>there is a lot less turbulence created by the laminar flow. And note,
>modern, non-wing paddles can significantly reduce turbulence by slicing
>the paddle outwards away from the kayak, just like racers and greenland
>paddlers.
>
>Well, the concepts above are quite clear to me, but I wonder how clear it
>is to the readers. I suppose I could put it down on a web page, with force
>vector diagrams, and with maybe even a bonus picture of me waving my
>hands.  Anyhow, I hope my definitions make sense, and maybe clear up a
>little confusion.

What is clear to Kevin is clear as mud to me.  If Drag were less than the
force...then the paddle is moving through the water.  I guess the laminar
flow is on the power face and the turbulent flow is on the other face... ??
But if that were true, then lift would be created on the underside of the
wing.

Lift...  Lift on a wing is created because there is a greater greater
distance on the upper surface of the wing between the leading edge and the
trailing edge of the wing.  Isn't this called the airfoil... corrolated
with "hydrofoil?"

What is a "wing paddle?" John Winters speaks of low-aspect ratio... what is
that?

I'm having a difficult time with this discussion not knowing the
vocabulary. I've looked for ads for a "wing paddle" but haven't seen any.
Perhaps that refers to the asymetrical design??  I'm reaching here.

Thanks

Robert


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