From: "Alder Creek Kayak & Canoe" <aldercreek_at_qwest.net> >> If you choose to define flutter your own way, it can mean anything you want. >> You're taking any form of instability to be flutter. If you can't agree on a standard >> terminology, there's no point is discussing anything. > > The Webster's II dictionary I have actually defines flutter: "to flap or > wave rapidly *and* irregularly." > I would say that any form of paddle instability that causes rapid and > irregular waving or flapping could be called flutter. Except that Webster's isn't a standard reference in the realm of hydrodynamics. My Webster's New World Dictionary (1976) defines oxygen as the most plentiful substance in the universe - which it clearly isn't. The English language often fails science and law - that's why scientists, engineers and lawyers can't be understood by anyone else and why life scientists stick with Latin in many cases. For science, etc, the language can't be general, it must be specific. That's my point wrt flutter. There are lots of forms of instability, but when most paddlers talk about flutter, they seem to mean the same thing. We can dig up names for the other kinds of instability, if we need to discuss them. > Seems what we're discussing here is more of a regular wave with a defined > wave shape and length. Maybe even a pulsed wave, caused by Karmen vortex > shedding. Calling it a wave is iffy, except in the context of having a regular frequency. If you call it a wave, that would influence the thinking of paddlers that are looking for it. It's only a wave in the sense that the sweep second hand of a watch can be described as a wave. And yes, it would be pulsed as in +on, off, -on, off, +on, off -on, off..., though the exact shape of "on" I could only guess. Vortices peel off the edges of the paddle on alternating sides, first one side, then the other. This tugs the paddle around, first one way then the other (as I said in another post, I can't see these; they seem to be swamped by the vortices that are caused by broken flow around the edge of the paddle, where vortices are visible at all). In a steady state environment, this frequency can be predicted -hence, wave like. Paddling isn't steady state, but there's a point in a draw-type stroke that will allow several oscillations, seemingly regular, to occur. Most of us have felt this at some time. Loosely holding almost any paddle and drawing it straight back will usually do it. BTW, several folks have suggested that angling the paddle reduces flutter by generating lift. I believe that they can angle the paddle enough to break the symmetry that can give way Karman vortex shedding without actually generating much lift. This intermediate point's existence would depend on the angle of attack at which stall would occur (I think). (Intermediate, of course, meaning between high drag and high lift states - sort of "relatively high drag without much lift but we got rid of vortex shedding") This set of complications is one thing that affects my lack of acceptance of "conventional" thinking on lift, wing paddles, Greenland paddles etc. But that's another story... > I also agree that all aspects of anyone's technique should be considered > when an irregularity like this comes up. We sell a tons of paddles and have > yet to see one that was so far out of line that *flutter* was a problem. Well, when one paddle works for John and another doesn't, I won't jump to the conclusion that technique is to blame. There are so many good paddles on the market, I don't see the point in sticking with one that doesn't work for him - whether or not it's his or the paddle's "fault". The paddles I've tried that flutter badly have been off the market for a while. As I stated in another post, I can see a case where the paddle is inappropriate for _him_ even though it's fine for others. If we can isolate the paddle as not part of the problem, then certainly, let's critique technique. I guess that I react when I see people go into "solution mode" when "analysis mode" hasn't finished. None of us has seen John or the paddle - I would prefer to give him the benefit of the doubt and have him try other paddles. If the problem is frequent with other paddles, we've narrowed it down. As you and I have said, in different ways, the majority of paddles sold today are good. Mike PS - I can't help but notice that the vendors on this list tend to recommend changing the paddler rather than the gear - or is that my imagination :-) PPS - I do get my back up when misquoted. A couple of times in this thread folks have suggested I said that paddles shouldn't flutter. In fact I have repeated that all paddles flutter, but some are better than others. I apologize if I have offended anyone with the apparent sharpness of my responses. *************************************************************************** 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/ ***************************************************************************
At 6:08 PM -0500 12/2/01, Michael Daly wrote: > >PS - I can't help but notice that the vendors on this list tend to recommend >changing the paddler rather than the gear - or is that my imagination :-) Sounds like a bad business practice if that's the case. It is easier to sell more product if you convince people that all they need is another "better" paddle. I suggested learning to deal with the paddle in hand because it was the paddle in hand and it seems a waste to go out and buy a different paddle when the one in hand will probably serve just fine with a small change in technique. Someone suggested offline that I think highly of the the Eddyline paddle. I have no opinion about the paddle, I've never laid eyes on one. It is just my experience that people learn to accommodate the apparent tendency of their paddle to flutter rather quickly, and they shouldn't throw the baby out with the bath water. >PPS - I do get my back up when misquoted. A couple of times in this thread >folks have suggested I said that paddles shouldn't flutter. In fact >I have repeated >that all paddles flutter, but some are better than others. I >apologize if I have >offended anyone with the apparent sharpness of my responses. I will plead guilty to not always completely reading the meaning of peoples posts and responding to what I thought they were saying instead of what they really were saying. -- Nick Schade Guillemot Kayaks 824 Thompson St Glastonbury, CT 06033 (860) 659-8847 *************************************************************************** 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/ ***************************************************************************
This archive was generated by hypermail 2.4.0 : Thu Aug 21 2025 - 16:33:25 PDT