Luff push twin foils

Discussion in 'Projects & Proposals' started by Xtractif, Oct 13, 2019.

  1. Xtractif
    Joined: Oct 2019
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    Location: Uk

    Xtractif Junior Member

    New to the forum interested in hydrofoils
    Small dinghy twin foils make very active sailing
    The AC boats are moving to lifting tri foils
    Do twin inverted T foils create to much drag for small boats?
    The wind/sup foils which are trimmed by body weight have more streamline form giving better lift and better control
    The moth/wasp foils are very basic foils
    Could they be improved using board foil designs
    Would twin foils work on small boats without lifting one foil
    Canted T foils should give more stability on a single hull?
     

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  2. Doug Lord
    Joined: May 2009
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    Doug Lord Flight Ready

    T-foils have been used successfully on many foilers from the Rave tri to the Vampire Cat and others. The Rave system(Rave 16, Osprey 18 and the 40' SKAT) uses wand controlled altitude control with dual ,independent wands which provides all the righting moment for the boat with downforce from the windward foil:

    Vampire
    VampireTexel2018_05.jpg

    Rave
    Rave Foiler.jpg

    Osprey
    Osprey 9-16-11 flying - Copy.jpg

    Osprey-flying bradfield last day.JPG
     
    Last edited: Oct 17, 2019
  3. Xtractif
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    Xtractif Junior Member

  4. Doug Lord
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    Doug Lord Flight Ready

    The Rave does not require crew movement. The Osprey does not require crew movement but allows it. The Bradfield foil system on those boats and the 40' SKAT can develop 100% of the righting moment required to fly with NO crew movement. Same with the Hobie Trifoiler foil system(designed by Greg Ketterman) that uses dual, independent, "feelers" to control altitude and provide all the boats righting moment-requires no crew movement.

    Hobie Trifoiler:

    Hobie Trifoiler google.jpg

    Dr. Sam Bradfields 40' SKAT:

    Skat bradfield 40 wand illustrated.jpg
     
  5. Xtractif
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    Xtractif Junior Member

    Doug but these are all huge cats or trimarans I’m asking about foils on solo dinghy not moth style but dihedral V etc
     

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  6. Doug Lord
    Joined: May 2009
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    Location: Cocoa, Florida

    Doug Lord Flight Ready

  7. Doug Lord
    Joined: May 2009
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    Location: Cocoa, Florida

    Doug Lord Flight Ready

    Note: the biggest advantage of the Bradfield and Ketterman foil systems is that they can provide 100% of the required righting moment. The AC 75 system with two main foils in the water could ,theoretically, do the same thing but downforce from the windward foil is against the rules.
     
  8. Xtractif
    Joined: Oct 2019
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    Xtractif Junior Member

    Doug but these are all huge cats or trimarans I’m asking about foils on solo dinghy not moth style inline but twin foils
     
  9. Xtractif
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    Xtractif Junior Member


  10. Doug Lord
    Joined: May 2009
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    Location: Cocoa, Florida

    Doug Lord Flight Ready

    A boat using Welbourn foils or similar is probably the least expensive foiler you can get, particularly if you design and build it yourself. Good Luck!
     
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