mercredi 10 avril 2013

AMERICA'S CUP - AC72: THE FOUR WINGS

AMERICA'S CUP - AC72: 
THE FOUR WINGS



One would expect that the aerodynamic teams of the three syndicates, Oracle Team USA (defender), Emirates Team New Zealand and Artemis Racing (challengers) would produce rather similar wings. Yet such is not the case!  To the contrary, it appears that the options are very different from each other, proof that individual scientists’ personality and experience produce unique solutions…




The wingsail of Oracle is a model of its kind: simplicity, soft forms, steerable trailing edge on the leading edge flap with a thick profile, more flexibility of the four vertical panels of the trailing edge flap with a thin profile.
The power will be there, and the team had difficulties to manage righting moment and unexpected movements in sudden strong wind

ETNZ one is in its pure form.  A straight-line leading edge, two flexible flaps in plan; the leading edge element is thicker than the one of the trailing edge, which is vertically divided in four panels. The center of pressure is lower than the Oracle and Artemis wings, and a slight complementary surface on the lower flap.  The entire system guarantees an amount of power, which was properly handled from the very first sea trials, the catamaran displaying a stable flight attitude on one foil. 

The first Artemis wing is more elaborate, with sinuous curves, divided in three elements. The first element is very large and shows a lenticular profile. The second and third flaps, with thinner profiles, are divided vertically into six panels; combined, the three elements resemble the wings of long-haul aircraft with flaps extended.

The second Artemis wing is intended to support simplicity: it is divided in two elements, and it preserves curves on the leading and trailing edges. The first flap has a thick leading edge profile; the second one is very thin and can be moved from the first one.

On the construction side we can see the same range of differences. The frame structure of Oracle wing is 0.64 meter long (2’1’’); it is 0.78 m (2’6’’) long on ETNZ, 1.05 m (3’6’’) long on Artemis I and 1,20 m (4') on Artemis II.


This analysis reflects that the power of the three wings is certainly not the same and each profile is quite unique at various points of sail. 



François and Jacques wish to thank Robert and Greg (CupInfo) for their assistance in the translation in English.

Their link: http://www.cupinfo.com
CupInfo: All about the America's Cup



8 commentaires:

  1. i think you have the first Artemis wing there. The new one is quite different

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  2. You're right! We have modified our comment and design... Thank you for your comment!
    Jacques

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  3. The aft wing elements should be moved to the windward side. Check:

    http://4.bp.blogspot.com/_83C0d9qWNoU/TTgqGCKhGhI/AAAAAAAAcKw/_HvS8W5VYaw/s1600/AC45NZ1D8_4383.jpg

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    Réponses
    1. Sorry for the delay of my answer...
      Again, you are right! Thank you for your advice. As you can see, the design have been modified.
      Jacques

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  4. Hi,

    Or should I say Bonjour?
    I'll stick with english...
    I wanted to say thanks for your blog; I'm a French Chocolatier, currently in Auckland and extensively used the informations you publish as a base for my last showpiece so I thought it'd be fair to share it with you.
    Here it is:
    https://plus.google.com/photos/111515162388971174864/albums/5882368811330308833

    Merci

    Frank

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  5. Thank you Frank and congratulation for your superb models!
    Merci beaucoup Frank ! Moi qui suis pris de chocolisme depuis l'enfance, je bave devant votre modèle. Bravo en tout cas pour cet ouvrage !
    Salutations rochelaises,

    Jacques

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  6. Hi,
    at the moment I am working on a project with the aim to compare the fluid movements around a mast-sail combination and a double wing. I would like to rebuild one of the Ac72 wings as a model, in order to perform 2D measurements in the wind tunnel. My question is whether you have precise data of the 2D cross section of one of the Ac72 wings.

    Thanks for helping and for offering this website,

    Tobias (Germany)

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  7. bonjour,(et désolé de faire du déterrage) je suis en classe de première et dans le cadre de mon TPE sur les hydrofoils je voulais vous demander si je pouvais utiliser vos illustrations.
    en l'attente de votre réponse
    cordialement

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