Re: [Paddlewise] Clarification?

I'm not even certain that we can get to the point where we can worry 
about angle of attack to achieve lift. Any kind of lift is going to 
require the paddle blade move perpendicularly to the direction of boat 
motion. This is either up-down or left-right motion. Paddlers arms are 
pretty short and don't allow much side-to-side motion (maybe 14 - 18"), 
and as long as we are sitting in the middle of a boat, vertical motion 
is limited.

The largest range of motion available to a paddler is available by 
reaching forward and pulling back (about 3' to 4'). It is possible to 
push the blade out to the side a bit while pulling back, but the range 
of motion is substantially limited. There does appear to be some 
benefit to swinging the blade out away from the boat, but this may have 
as much to do with keeping the blade in "clean", undisturbed, still 
water as it does with generating significant "lift".

Since it is so hard to move the paddle in a manner to generate thrust 
with lift, it would seem to be jumping the gun to analyze the virtues 
of different foil configurations. The only stroke I've seen that has 
the potential to generate lift is the wing paddle stroke, and it isn't 
even established they really benefit from lift. We can produce all 
kinds of equation demonstrating the benefits of high-aspect ratio, but 
if the blade doesn't move right, what is the point?

Nick


On Sep 9, 2004, at 12:43 PM, John Winters wrote:

> Another problem we should condsider in the quest for high lift has to 
> do with the difficulty in maintaining any angle of attack through the 
> water much less the ideal angle of attack. Can paddlers actually 
> achieve and maintain the desired angle of attack? How does one 
> compensate for the variability in angle of attack due to the ever 
> changing flow direction in waves? (with the wave at the crest, 
> vertical down on the front face, against the wave direction in the 
> trough and vertically up on the back and, of course, everything in 
> between)

Nick Schade

Guillemot Kayaks
824 Thompson St
Glastonbury, CT 06033
USA
Ph/Fx: (860) 659-8847
http://www.guillemot-kayaks.com/
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