Peter wrote: <Snip>>>>Having the ability to flex gives the designer/builder one more feature to adjust and optimize. That option is not available in a hard shell design. Too much flex takes energy from the paddler and makes it hard to control, too stiff tends to knock the paddler around in rough conditions (also making it hard to control).<<<<< I agree with most of what Peter says and even half agree with the above, but I would like to point out that flexing isn't the only way a kayak can avoid being knocked around in rough conditions and that any flex at all is absorbing some propulsive energy from the paddler. There are many aspects of a kayak's shape that can deflect the blows and forces it may be subject to in rough conditions. A rigid kayak doesn't have to feel like it is being knocked around when the conditions get rough. That depends on its design (and I think that is a very important aspect of a kayak's design). Peter, what formula did you use to calculate the Reynolds number of a kayak at about 2 billion? I don't recall the Reynolds number for a speeding golf ball but for a speeding sea kayak it is likely to be in the 7.5 million range (using the formula Re = (speed)*(LWL/1.2791)*10^5) and your speed and LWL figures (6 ft./sec. and 16 ft.). Note: 1.2791 is the Kinematic viscosity of salt water at 59 degrees F. (the temperature and salinity I believe towing tank results are corrected to) and 6 ft/sec. is about 3.5 knots. Even at 33 degrees F. the viscosity of 3.5% salt water would be 1.9323 so the Re would then be about 5 million according to my calculations. Can you tell me where I'm going wrong here? Speed in the formula is in units per second and LWL is in the same units of length as used for speed. I could roughly calculate the golf ball range from this if I knew the viscosity of air and the diameter of the ball (or took the time to look them up). Matt Broze www.marinerkayaks.com *************************************************************************** PaddleWise Paddling Mailing List - Any opinions or suggestions expressed here are solely those of the writer(s). You must assume the entire responsibility for reliance upon them. All postings copyright the author. Submissions: PaddleWise_at_PaddleWise.net Subscriptions: PaddleWise-request_at_PaddleWise.net Website: http://www.paddlewise.net/ ***************************************************************************Received on Fri Oct 01 2004 - 02:20:29 PDT
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