Mike Edelman wrote: Move a paddle or wing through a medium and it generates lift and drag. The more efficient the paddle and stroke, the more lift per unit of drag. Not necessarily true. Both the vectors we call "lift" and "drag" have components in the direction we want, the direction which drives our boats ahead. The most efficient paddle is the one which maximizes the vector in the direction we need, whether the force is produced by lift or drag. To really get a handle on this topic, we should stop thinking about lift and drag, and look at the force pushing the boat forwards and the steering force produced at right angles to the boat's motion. The lift and drag concepts were invented to make airplanes fly. Lift gets the airplane off the ground (good!), drag holds it back and has to be overcome by the engine force (bad!). In our situation, the pressure regime formed around our paddle can be transformed into the vectors we are interested in (drive and steering), as opposed to the ones that aeronautical engineers find useful. Unfortunately, all the research on air and hydrofoils has been done in terms of lift and drag, so it makes it tough to apply their data to paddles. Drag can be good, lift can be bad, depending on which way it is pointing relative to the way we are trying to move the boat. Rob. *************************************************************************** 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/ ***************************************************************************
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