Re: [Paddlewise] Subject: Re: tank tests

"Matt Broze" <mkayaks_at_oz.net> wrote:

> I too have questions concerning the suitability of a tank of standing water
> for adequately representing a paddle stroke in a moving kayak. Possibly if
> the tank is big enough so that the paddle and the water flow and vortexes
> coming from the paddle aren't being effected by the sides and bottom (or
> ends) of the tank a simulation could be done if the paddle is only moved
> with the same force it is under during a normal paddle stroke rather than
> the hard strokes during a fast acceleration that a paddler next to a tank 
> is
> likely to actually simulate. A paddler next to the tank is more likely to
> simulate the tug-of-war victims than the cruising paddler. Maybe you could
> mount the paddler (or mechanical paddle machine) on tracks with adjustable
> drag and have it move as the paddle is worked in the trough.

This will not be quite what you are looking for, Matt, but it is a step in 
that direction:

Dedicated sportfishers have used underwater videocams for many years, very 
effectively, to detail and document the relative attractiveness of various 
lures (and their action) to salmonids and other finny creatures.  A videocam 
could be affixed behind a kayak's stern (how's that for one hell of a draggy 
skeg!), and streamline contrast fluid could be introduced from small nozzles 
on the ends of wands placed ahead of the paddle to detail at least some of 
the manifold wondrous phenomena people think occur around paddles.  (As a 
one-time airfoil experimentalist -- built two wind tunnels as a teenager -- I 
am a full-blown skeptic of anything but empiric study of foils in fluids.)

No tank needed, and no concern about edge effects therefrom.  Outfit the 
paddler with monitoring to measure VO2 max, effort, respiration rate, etc, 
and maybe you'd get somewhere on the question of relative "efficiency" of 
various paddles.  There must be some demented university physiologist or 
biomechanician who could be convinced this was worthwhile.  I've certainly 
done sillier things as research, and gotten paid to do them ... oh, oh, I'm 
letting secrets out.  Bad chemist.  Back to your test tubes, Dave.

--
Dave Kruger
Astoria, OR
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