34th America's Cup: multihulls!

34th AC

Luna Rosa Specs from The Daily Sail:

Vital statistics

Hulls length: 22 m
Beam: 14 m
Wingsail height: 38 m
Maximum draft: 4.40 m
Weight: 5,900 kg
Crew: 11

Wingsail: 260 sqm
Jib: 80 sqm
Gennaker: 320 sqm

Projected top speeds

Upwind: 25 knots
Downwind: 42 knots

 

Quote:
Originally Posted by Doug Lord
If the system had not had a malfunction of some sort there is no doubt whatsoever that the boat would not have pitchpoled.

Well said by someone who has never pichpoled a multihull.

I think post 830 by Stephen Ditmore (who I hope still has a home) sums it all up the best.

 

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What?! I used to sail a Hobie 16 and see how close I could keep the lee bow to the water w/o pitchpoling. That resulted in a number of pitchpoles. It was a blast!
Why would you make such a statement?
If you're basing that on post 834 they were RC models I designed and built and they showed how resistant a foiler could be to pitchpole. Normal RC multihulls are extremely prone to pitchpole.

 

34th AC on foils!

TNZ ploughing the field-look at the drag coming off the lee main foil:
click to see it more clearly-

 

Now THATS what I call "Air Entrainment".

 

Might look draggy Doug but Im going to go out on a limb here and say they are going to kick Larry and Russell's asses no problem, particularly after Jimmy's wee swim setting the program back so far.

 

Terry Hutchinson has exceeded expectations before, though. Let's not write him off.

 

and now the news is that Locke Peyron (forgive me if I've spelt it wrong) is with Artemis. The AC34 is going to be incredible! Peter oh by the way spray drag is a very small component of the drag equation, the soft jib is the next problem.

I've just looked at the above ETNZ photo in detail and there is a clear divet in the surface of the sea above the foil. Its really sucking hard, excellent photo!! Peter

 

Well, there are some mighty lifting forces acting there, like 7 odd tons of platform and wing to support, in a small area - did you think that would be a svelte little parting of the waters?
ETNZ is like Russian truck crossing a river, (maybe tractor-like) all brute power, not some effete little contraption that keeps losing its balance and drowning.

 

34th AC

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TNZ was the first to foil and first to foil well. While that picture shows a lot of drag I think it is caused by flying the windward hull. That makes the foil take a wierd angle. I've seen other pictures that show a lot of spray(typical of a surface piercing foil) but nothing like this. I'm certain that when they race the boat will be flat 95% of the time.
I'll bet that Oracles "L" foil is the faster system IF they can learn to fly it and iron out their control problems.

 

34th AC

Luna Rosa sailing, bird flying:

click-(Pictures from SA Luna Rosa thread)-2nd pix-notice anything missing?

 

I've been hoping some one would do speed comparisons with and without the foils. NZ/Luna have the perfect opportunity to see if straight daggers make sense for the course.

If the rules don't prohibit log canoe hiking boards Oracle could send everyone a looong way aft when they turn down.......

 

On Luna Rossa's first outing they don't seem to have boards? They do have several boards because they were in the video LR did for their launch day. The boards in the video didn't seem to be finished. Their taking little steps. Peter S. Gary B there are some excellent russian truck videos out there. Some of their trucks should be called submarines. But TNZ are now pulling out the boat and doing its first upgrade. In 10 days we shall see even more speed. Yippee. Peter S

 

Peter don't get to excited.

Reason. Article they are on to it.


http://www.stuff.co.nz/sport/other-sports/7898138/Team-NZ-to-take-AC72-testing-to-next-level



Luna Rossa is sailing the old course AC Auckland. They will be able to compare notes with ETNZ stats no doubt. Foils verses no foils on the same track Especialy if they both have AIS.

OC

 

Hi Oceancruiser - I'm sure they know the answers to that already. Several photos show they have been using different foils on each side and they certainly would have developed velocity polar plots of everything they have done. They are data logged to the max & have cameras on nearly everthing. So all of the "on paper" results are in. Now they have to move onto what Dalton calls "mechanics" to improve sailors movement efficiency and functional stuff thats too hard to figure on paper. The two boat stuff is about training and sailing more than pure boat speed. I think Luna Rossa's foils may have been photoshoped out? More intrigue. Peter S