IMOCA 60 2016-2017 Foil Assist

Discussion in 'Sailboats' started by Doug Lord, Mar 31, 2016.

  1. Doug Lord
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    Doug Lord Flight Ready

    2015 version of this thread: http://www.boatdesign.net/forums/sailboats/2015-imoca-60-foil-assist-52338-4.html
    ----------------------------------------------------

    This is a radically new set of foils for Bastide Otio with an interesting story from The Foiling Week. http://www.foilingweek.com/blog/2016/03/des-foils-pour-bastide-otio/

    The studies were conducted by a small group of experts in the aviation industry, discreetly. The idea was to do differently from the other 60 'equipped with foils in 2015 and to have independent thinking, without any pressure. Computers and brains were heated for weeks to create an original, simple and hopefully effective.

    The team of researchers, led by Laurent Prunet, worked to significantly improve the performance of Bastide Otio downwind without degrading them into the wind, which can represent 30% of the conditions encountered in the Vendée Globe.

    It is simply to add foils existing drifts, allowing in particular to use the two appendices downwind to lift the boat and get on plane. On the contrary, when the drift is rising, the carrying surface is flush with the hull not to slow down the boat in light air, for example, where we saw the new boats severely handicapped.



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  2. Doug Lord
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    Doug Lord Flight Ready

  3. captainjo
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    captainjo Junior Member

    Cool upgrade of an Imoca :cool:

    It's quite near the configuration of the 888 mini transat :

    [​IMG]

    I think too that upwind performance in light and moderate winds can make a difference, like in the last Transat Jacques Vabre between PRB and PB VIII.

    Captain'Jo
     
  4. Doug Lord
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    Doug Lord Flight Ready

    Good point-very much like 888!
     
  5. Doug Lord
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    Doug Lord Flight Ready

    IMOCA 60 Foil Assist

    PRB rudder foil with tubercles, top; Hugo Boss illustrating "foil assist" 2016!

    [​IMG]

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    Last edited: Apr 5, 2016
  6. Doug Lord
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    Doug Lord Flight Ready

    IMOCA 60 Foil Assist

    I'm reluctantly posting this link from "The Foiling Week" that includes a video purporting to show "foiling daggerboards " that lift a "foiling IMOCA" 60 "out of the water. In fact, these boards are at the same level of FOIL ASSIST that the 60' tri's have been for 30 years with their lifting ama foils. That has changed recently with the MOD 70 Gitana using a foil system that does ,in fact, lift the boat clear of the water.
    These IMOCA 60's are not yet foilers, but they are effectively using foil assist to reduce the load on the hull. You'll note that none of the IMOCA boats(as best I can tell) are using rudder T-foils-a necessary ingredient for any foiler with a forward main foil ,if it is to actually fly. It will be interesting to see what these same voices say when the boats are actually flying!
    http://www.google.com/search?source...=1T4DKUS_enUS258US259&q=boatdesign.net/forums
     
  7. Doug Lord
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    Doug Lord Flight Ready

    Maitre COQ

    New foil for Maitre COQ (see post 2 above) :

    [​IMG]
     
  8. Tanton
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    Tanton Senior Member

    Foiling leeboard

    Not fooling around.
     

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  9. Doug Lord
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    Doug Lord Flight Ready

  10. Stumble
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    Stumble Senior Member

    They need to talk to some old catamaran sailors. That hum, commonly called Hobie Hum is fixable with a pair of scissors and about five minutes of time. It just takes a quick scoring of the trailing edge to get rid of it.
     
  11. R.Finn
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    R.Finn Junior Member

    Hugo Boss has a higher number of more complicated shapes dragging through the water at one time than on a Hobie 16 or A-Cat. I'm not suggesting it the hum can't be cleaned up, but in this case, I bet it's a lot more difficult that you think.
     
  12. Stumble
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    Stumble Senior Member

    R.Finn

    You may be right, but that sound is exactly what is experienced on Hobie cats, foiling a-cats, non foiling A-Cats, basically the entire stable of fast beach cats. In every case it's caused by mold perfect boards with a squared off trailing edge. The solution is to scrape a pair of scissors down the foil, one blade acts an an index against one side, the other removes just a sliver of material. The slight asymmetry stops the harmonics from forming.
     
  13. Doug Lord
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    Doug Lord Flight Ready

  14. Doug Lord
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    Doug Lord Flight Ready

    IMOCA 60 Foil Assist------noise and vibration

    From "Foilers!" a good article on the noise and vibration on the 60's:
    https://foils.wordpress.com/

    It's in French but you can google translate and it still makes sense-mostly.
     

  15. Doug Lord
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    Doug Lord Flight Ready

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