34th America's Cup: multihulls!

Discussion in 'Multihulls' started by Doug Lord, Sep 13, 2010.

  1. Leo Lazauskas
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    Leo Lazauskas Senior Member

    Still a slim chance there will be another race in about 6 minutes...
     
  2. Leo Lazauskas
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    Leo Lazauskas Senior Member

    They are in the start box in what might be the last race...

    LOL. Windspeed went over the limit again, just as they were about to start.
    No more racing today.
     
  3. andybrnr
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    andybrnr Junior Member

    Ah, so close.
     
  4. Blackburn
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    Blackburn Senior Member

    ...

    The Artemis curse struck again.

    Ah well, a postponement is to be preferred over another ETNZ win at this point.

    :)

    I'm sure I'm imagining things, but I wonder if the pod and forward strut on Oracle are now shorter. The pod is wonderfully slim in any case.
     
  5. Leo Lazauskas
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    Leo Lazauskas Senior Member

    Orcs had the advantage of a port start so they won't be too happy.
    They will have that tomorrow, but then NZ have the advantage, if not two in a
    row(?)
    It should be all over by Monday and drones can get back to droning. :)
     
  6. petereng
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    petereng Senior Member

    nacra 17's and Olympics

    Hi Leo - The Olympic machine is very difficult to change.The Olympic machine also is not interested in events that feature machinery, or devices very much as its about the athlete not the machine. Then theres the problem with the preferred "stadium" events ie the Olympics prefer events that occur in stadiums so the partipants and TV etc can be controlled/marketed easier. Many years ago I was involved in building bicycles for the Olympics and it became very clear that if you pushed the technology card you very soon came under a lot of pressure. Sailing is then further complicated by the ISAF who send mixed messages and have no clear future picture of what sailing is and who how what works. Its very complicated. So for now make the N17 work really well, make it look good on TV have great looking couples win the races and then push for another multi class, perhaps. Oh yes and the other aspect of it is continuity. The discus throwers are still throwing the same discus so there is a continuity in the value of the Gold medal. If the equipment changes its argued the athletes cache is different so Finns it is! So in short expect Olympic class changes to be slow, extreme sport red bull changes to be fast. So perhaps forget the Olympics if its change you are interested in Cheers Peter s
     
  7. Blackburn
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    Blackburn Senior Member

    ^^^

    Morelli made some comments about the Nacra 17 in an item which I posted yesterday; an article in which he has interesting comments on several topics:

     
  8. Blackburn
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    Blackburn Senior Member

    ...

    Back on the topic of the wind limits, there was mention of it in yesterday's skippers' press conference;

    Dean Barker was asked why ETNZ wouldn't now agree to changing what became new rules in June, and he gave a quick summary of what had happened:

    ... Gee, I wonder why Oracle had then favored a top wind speed of 20 knots; something to with their boat otherwise self-destructing perhaps?

    lol

    If the 25 knot limit had been chosen, instead of the compromise 23, then most of these 6 postponements (so far) would not have happened, I suppose.
     
  9. Leo Lazauskas
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    Leo Lazauskas Senior Member

    It also begs the question of restrictions on future venues.
    If the foiler fangirls have their way, then the AC will only be able to be held in
    waters with no waves over about 1m. Wouldn't that exclude a lot of places
    like Fremantle from ever holding the AC again? (Of course that would first
    require something miraculous to occur!)
     
  10. Doug Lord
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    Doug Lord Flight Ready

    34th AC

    ===================
    You didn't listen to Spithills answer to that question in the same press conference??
     
  11. Doug Lord
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    Doug Lord Flight Ready

  12. RHough
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    RHough Retro Dude

    The unwritten intent of the Deed was to have the Club holding the Cup defend in the home water where they hold their annual regatta.

    This would mean the Defender would likely have boats to defend with that are extremely well suited to local conditions. IMO that should be the biggest factor in what the defender would agree to as far as design. If your home waters make foilers a poor choice, you write a protocol to exclude them.

    There are few places called home waters by Yacht Clubs that have 20+ and 1m+ during their annual regatta. SF and Fremantle are exceptional in that regard. I seem to remember that the world average is about 10 knots? and Force 3 -4 should see fully developed waves about 1m.

    The AC72 foilers will probably work in the home waters of the vast majority of Clubs.
     
  13. RHough
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    RHough Retro Dude

    Going back to the foils. (I should know better)

    I have no idea what the AoA / Cl curve looks like for a foil that cavitates. I've looked at these curves for Low RE fois when I was playing with glider design. A foil that stalls gradually and requires a small reduction in AoA to get flow reattached is much less stressful to fly.

    I have to assume that foil performance as a foil is forced into cavitation is similar. But since cavitation is not an issue for foils flying in air I don't know where to start looking for that sort of information.

    As I understand it cavitation is related to speed more than lift production? That a foil can cavitate at a zero lift angle?

    All new science for me.

    Randy
     
  14. Leo Lazauskas
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    Leo Lazauskas Senior Member

    Thanks, Randy.

    Why would a Defender bother excluding them explicitly?
    If foilers are a poor choice for their local conditions, and the opponents
    choose them, isn't that their own silly fault?

    An average of 10 knots means that we would not often see the speeds
    attained during the present AC.

    Hopefully we will know more about what we can expect after today's racing
    (unless it's declared a shopping day again!)
     

  15. RHough
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    RHough Retro Dude

    I think it would be a CYA sort of thing. It eliminates a variable. How silly would the Club feel if the "normal" conditions that would prevent foilers from winning did not materialize ..? Sort of a reverse of what we are seeing in SF.

    It would be inconvenient for me for the AC to continue much longer, I am seriously behind on some tasks ... therefore I predict a win for USA so that I'l waste another day on the net and scheduling around a stupid boat race.

    Cheers,

    R
     
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