35th Americas Cup: Foiling Multihulls!

Discussion in 'Multihulls' started by Doug Lord, Sep 26, 2013.

  1. Doug Lord
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  2. Corley
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  3. Doug Lord
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    35th America's Cup on Foils!

    Thanks a million for that ,Corley-I hadn't found any video! Too bad it is such light air, or should I say too bad the boats won't foil in that breeze(they could)... Makes the point about light air foiling like what the Quant guys(and others) are shooting for- foiling in 5 knots of wind (or less).
     
  4. Doug Lord
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  5. Doug Lord
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  6. DouglasEagleson
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    Do these guys use water ballast in the upwind hull? Even with foils you need water ballast.
     
  7. Doug Lord
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    Not in the AC 45's but the largest(and oldest) and one of the fastest ocean going foilers Hydroptere uses water ballast in the windward ama. And a very fast Australian twin rig foiler(Spitfire) also uses water ballast. Some other non-foiling multihulls use waterballast in the main hull. Ballast can be beneficial on any fast boat.......
     
  8. waynemarlow
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    waynemarlow Senior Member

    BTSport ran quite a longish hour or so of the racing
     
  9. Doug Lord
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  10. Doug Lord
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  11. CT249
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    CT249 Senior Member

    Why? Are you assuming that you are right and the AC sailors are wrong?
     
  12. Doug Lord
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    35th America's Cup on Foils---Oracle

    From Scuttlebutt the other night:

    CRACKING THE CODE
    If you read the book, The Billionaire and The Mechanic, which was originally released before the 34th America's Cup and then re-issued after the 2013 event, there is an excerpt in the later edition where Oracle Team USA made a wing trim discovery that significantly contributed to their comeback in the series:
    That evening, Russell (CEO Russell Coutts) and the design team reviewed video taken from helicopters during the day’s racing. One of the aerial shots, looking directly down on the wing of New Zealand’s AC72, caught their attention. The intriguing video was stopped and slowly backed up, and then one frame was frozen on the screen. Everyone in the room focused on the angle of the Kiwis’ wing flap. One of the team’s senior designers broke the silence. “Holly sh#t! It looks like they’re sailing upwind with a lot more camber in their wing than we are.”
    They carefully measured the frozen image. It was a revelation: the Kiwi’s wing flap was set at a forty-degree angle to the wing’s main element. That was in stark contrast to USA-17. The American catamaran raced upwind with its flap set at thirty degrees. “That’s got to be it,” said Russell, shooting up from his chair. “Nothing has made any sense up until now. The computer models say our boat is faster than they are upwind, but the models assume the wings have the same camber and trim. They’re sailing with radically more camber in their wing than we are. More camber, more lift—more lift, more power upwind. We thought going beyond thirty degrees of camber would create too much drag. Obviously we were wrong.” With Team USA down six races to negative one....
    Over the next few hours the engineering and design team, including (engineer Joseph) Ozanne, designed a series of related modifications that increased the camber of the wing, lowered the center of effort, and moved the overall loading back to better balance the boat. The team’s boatbuilders had to physically modify the structure of their catamaran so the wing flap could be bent beyond thirty degrees, all the way to forty degrees—and even more. The builders would be working all night.....

    - Peter Brown
     
  13. waynemarlow
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    waynemarlow Senior Member

    Wasn't Tom Speers revelation about the rudders part of that or am I thinking about something else.
     
  14. Doug Lord
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  15. Corley
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