New Clubswan 125 curved daggerboards

Discussion in 'Hydrodynamics and Aerodynamics' started by H20DESIGN, May 11, 2018.

  1. H20DESIGN
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    H20DESIGN New Member

  2. Doug Lord
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    Doug Lord Flight Ready

    The curved board develops all the lateral resistance for the boat in addition to providing some vertical lift for foil-assist. Foil-assist can reduce the wetted surface of the boat and may add some righting moment*. The daggerboard is required with the canting keel since, when canted, the keel develops very little lateral resistance.
    Curved boards have been used on racing monohulls as well as on catamarans and trimarans for many years.
    *depending on the position of the center of lift relative to the boat CG.
     
  3. H20DESIGN
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    H20DESIGN New Member

    thanks for the answer.
    but from the desing point of view,
    if they have the size to be retracted and completely hidden inside the boat, how can they have enough size to generate all the lateral force required (for a 125ft)?? taking into account that for the structural resistance of the foil, it cant reach the edge (some part of the foil should always stay inside)
     
  4. Doug Lord
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    Doug Lord Flight Ready

    The board is curved-so is the trunk- which will allow a longer board to be stowed inside as compared with a straight board. Is there some reason the board can't come up through the deck? The render doesn't look very detailed to me-perhaps some elements are missing?
     
  5. H20DESIGN
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    H20DESIGN New Member

    I suppose it doesnt come out throught the deck for aesthetic reasons.
    but when it is deployed underwater , I think there should always be a big part of it that remains inside.
    thats why I think there is not enough lenght for the board.(asuming at least 1 meter or more that is always inside)
     

  6. philSweet
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    philSweet Senior Member

    It might be one long board that shuttles right on through. Some of it can always be sticking out that way.
     
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