S1223 heavy lift air foil rigid sail wing.

Discussion in 'Hydrodynamics and Aerodynamics' started by markstrimaran, Jul 29, 2015.

  1. markstrimaran
    Joined: Dec 2014
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    markstrimaran Senior Member

    Random idea. I am sure it's been tried. What would be the best foil number for a 8 mph hull speed. I was reading the threads today and thought back to something I pondered a few years ago.
    A rigid wing sail. 20 foot long about 4' wide. That was mounted on a 10 foot spar. So it could teater totter. As for tacking, and being multi directional.
    Rigged up on a trimaran. Single or perhaps two. On the outriggers.
    Completely rigid with no moving parts.
    The mast would fit inside the wing and act as a fulcrum point when tacking.
    Carbon fiber and glass construction.
    Thanks for your IMHO.
    I am a welder by trade and have hours and hours to ponder things well burning wire.
  2. Doug Halsey
    Joined: Feb 2007
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    Doug Halsey Senior Member

    Here's one example (from C. A. Marchaj's book Aero-Hydrodynamics of Sailing). There are other examples discussed in old AYRS bulletins. I don't think any of them were particularly successful.

    There is no best foil shape, for a given hull speed. There are many other factors involved. This might partly explain why they did not do better. Contrast the rigid "one-size-fits-all" shape with the wings on the C-Cats & America's Cup boats which can effectively vary their camber (via flap angle) & twist to suit the conditions.

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  3. Erwan
    Joined: Oct 2005
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    Erwan Senior Member


    The S1123 can achieve a hight lift coef, for sure.

    But to deliver this high HP it requires 20% of laminar BL on the low pressure side.

    Unfortunatly, AFAIK within the atmospheric BL, above water surface, natural turbulences will preclude this BL to be laminar.

    So if you play with XFOIL, set the NCrit @1 or 2 or fit a fixed transition@5%

    You'll find the max Cl to be significantly lower.


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