AC 36 Foiling Monohulls

Discussion in 'Sailboats' started by OzFred, Sep 13, 2017.

  1. Konstanty
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    Konstanty Junior Member

    AC36 - Section by main sail (1).jpg AC36 - all (1).jpg I'am sorry but I have to publish drawings one more. There was a mistake in the previous drawings. Sails shall be directed to the side opposite to the inclination of the keel. AC36 - sheet1.jpg AC36 - sheet2 (2).jpg AC36 - sheet3.jpg View attachment 141387 View attachment 141388
     

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    Last edited: Jul 12, 2018
  2. Doug Lord
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  3. OzFred
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    OzFred Senior Member

    According to these guys, the windward foil will be allowed to provide downforce to make the boats more controllable. Tough to listen too, but interesting none the less.

    There are also comments about allowing feedback systems from the flaps, perhaps so they can detect when conditions for ventilation are forming and prevent it (because ventilating the windward foil when you're dependent on it for RM is a high risk scenario). It seems they are still searching for ways to make the boats perform as expected.

     
  4. Doug Lord
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    Doug Lord Flight Ready

    Man, that has got to be the all time worst AC video I've ever seen! Good news about downforce-seemed silly to not allow it....Also independently moving flaps on the same foil-but that may have already been legal.
    Most boats that use downforce for RM use symmetrical foils-I wonder if that will be the case here. Also, will the main foil(or foils) have a positive angle of incidence to start flying and change it for downforce? And will the main foil(s) at takeoff lift around 80% of the load?
     
  5. Dolfiman
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    Dolfiman Senior Member

    Within the "Foil racing conference 2018" held in France last April, this is here below the video of the one dedicated to the next AC design, with Benjamin Muyl/ NAval Architect in the team Land Rover Bar and Gwenole Bernard / Engineer and Naval Architect, previously in Luna Rossa team, then Groupama team during the last AC, currently in the Macif team with Francois Gabart for the upgrade of the Ultim Macif, and he will join again Luna Rossa design team for the next AC. Video in French, I have picked up some key comments :
    - This new concept comes from a dialogue between the NZ design team (Dan Bernasconi) and the Luna Rossa one (key person being Martin Fisher)
    - Principle : all underwater adjustments (not visible, mostly foils) are on batteries, all visible (by the public) adjustments (mostly sails) are by crew force and skills
    - The big question (mentioned several times) : how we can accelerate, what happens below 10-12 Knots ( boat speed), the use of the Code 0,
    - mast : the top 4m and the bottom 1m are open to various systems of adjustments
    - sails : 1 skin for jib and Code 0, open to 1,2 or more skins for the main ....
    - foil wings open to design , but must be symmetrical and tip to tip span limited to 4 m
    - foil arm mechanism dedicated to arm maneuver (up or down), not for dynamic tuning of the foil wings. The windward foil should not be used to increase the RM
    - jib self tacking prohibited, cause : should be a crew ability affair
    - hull : no scow bow, they don't know why this rule (Italian reluctance for unaesthetic silhouette ?)
    - how to manage the heel -pitch without controller : they are prohibited for races but likely will be intensively used on prototypes to understand how it works, to identify the cause/effect relations.
    - 6 foil wings authorised per team, can be changed from one day to another a priori, expected wind depending.
    -it will not be a low cost AC, which can be seen a paradox as NZ team has (or had) not a big budget, 150 M€ to have a win chance ?
    All videos of thi Foil racing conference are in :
    [Retour sur] La Foil Racing Conference 2018 - BDI http://www.bdi.fr/fr/retour-sur-la-foil-racing-conference-2018/
    The video on the AC one :
     
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  6. Doug Lord
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    Doug Lord Flight Ready

    Dolfiman, one of the interesting developments in the(horrible) video in post 453 is that, apparently, downforce is now legal in the AC 75. Haven't read any followups though.....
    Thanks very much for translating the comments !
     
  7. Dolfiman
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    Dolfiman Senior Member

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  8. Doug Lord
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    Ineos Foiler Proto: (Note the "amas" on each side of the boat-stability problems?) I discovered after some messing with numbers that to build a model(65-72") of the AC 75 I would need to have a deep fin keel +bulb to have enough ballast for decent performance with multiple rigs.
    More from Sail-World: https://www.sail-world.com/news/207932/Images-of-the-INEOS-Team-UK-test-boat

    AC 75 28' proto.jpg

    AC 75 Ineos proto amas-7-22-18.jpg
     
    Last edited: Jul 22, 2018
  9. Doug Lord
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  10. Doug Lord
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    Doug Lord Flight Ready

    AC 75 (NZAC) Foil Geometry: (from Sail-World)

    AC 75 foil geometry-from sail-world.jpg
     
  11. PNW sailor
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    PNW sailor Junior Member

  12. Doug Lord
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    Doug Lord Flight Ready

    See post 459 for facebook video.It's somewhat clearer than the youtube video for some reason......
     
  13. Doug Lord
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    More on the INEOS Test boat from Scuttlebutt Eourpe:

    INEOS America's Cup test-boat takes flight (See post 459 or 461)
    The first video of the INEOS test-boat foiling in the Solent off Portsmouth UK - where Ben Ainslie's America's Cup team are based. The video appeared on the Facebook page of the London Corinthian Sailing Club, posted by Harry Aitchison.

    The foiling test boat is a modified Quant 28 design adapted to incorporate AC75 style foils as a test-bed for the team's prototype foil designs.

    Rolled out a couple of weeks ago the INEOS Test Boat has been undergoing safety testing in the Solent outside Portsmouth Harbour.

    The Quant 28 was designed by Hugh Wellbourn, developer of the "Dynamic Stability System" - a horizontal foil that can be extended to leeward to give a monohull more righting moment.
     
  14. Doug Lord
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  15. Konstanty
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    Konstanty Junior Member

    Last edited: Jul 28, 2018
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