Team NYYC

sailman

sailman

Super Anarchist
8,372
480
Portsmouth, RI
The_Alchemist said:
In the interview with Goodison he talked about how they feel there is so much better control of the main when you use a boom.  He says that he is constantly asking for more buttons on his sail trim controller so he can try new adjustments. Another interesting point he made is how you can really change the tuning of the sails with just the mast rotation.  It sounds like you could really sandbag it by just making some subtle changes in the mast rotation that may be hard to detect.

( https://yachtracing.life/the-yacht-racing-podcast-americas-cup-special-part-2-paul-goodison/ )

I think that AM still has a tremendous amount of room for improvements in their maneuvers.  Even the broadcasters mention how they were not as polished on their turns and you could see them lose ground on every turn.  I think they were way too conservative and losing speed and VMG.   You can see them out making quicker turns and dropping the second foil much later.
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Sounds like they need a good Penguin sailor to trim main!

 
I

I14RACER

Member
199
185
Maryland, US
RMac said:
If "better control" means the adjustment points holding their position better, for sure.  I originally thought the booms would be superior as you have a stiffer control member so wouldn't have the sail changing with wind stretngth. BUT.  The incredible depth of the mains means that the boom is a limiting factor. I mean you can ease both outhaul rams to get the clews fwd, but eventually the shape of the boom is distorting the bottom of the sail, and you also have no (or at least less) batten control of the shape of the foot. The boats with the weirdo battens/guys/rams, panels are able to make the mains incredibly deep, and then send them right back to flat (ish) as the boat accelerates.  I think out of turns and in light air the soft booms are better. 
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However. This only really impacts at any level just above or below the boom. Their boom is a deck sweeper, contoured to follow the deck shape, so the distorted portion is nominal. They are still sealing off the flow at deck level.

They must figure that this distortion is of little consequence compared to the improved sail control of a stiff boom. Otherwise you’d see them adopt it like all others have.

 
Indio

Indio

Super Anarchist
10,970
884
Auckland
NZK said:
Patriot's silhouette has always reminded me of a particular style of chef's knife...
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LR-PP LR-PP.JPG

Team Brexit Ineos Ineos Chopper.JPG

AM

UCUC3345-AM.jpg

ETNZ ETNZ-honshu.jpg

 
A

accnick

Super Anarchist
4,051
2,969
pluscount said:
If you know anything about 1911 pistols, this particular model is high on flash and low on function.  Are  you comparing it to ETNZ?
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.45 ACP is the only way to go. Makes an unforgettable  impression on whatever is on the receiving end.

 
MaxHugen

MaxHugen

Super Anarchist
2,141
1,143
Port Macquarie, NSW, Australia
erdb said:
Aspect ratio is defined as span / mean chord. The confusion comes from how you get this ratio. For simplicity, instead of calculating a mean chord, you can use span^2 / area. It's the same thing, because area = span x mean chord, so basically you're dividing span^2 with (span x mean chord) and arrive to the same span / mean chord ratio.

For the sails, I get the induced drag from the vortex sheet, for the foils, I use span^2 / area.
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OK, I thought you were also calculating the sail induced drag from @Basiliscus 's previous posts.

Still looking for a good tech article that considers end plate... and how to deal with 'partial' end plate effect.

 
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