35th Americas Cup: Foiling Multihulls!

I think their explanation for the one-design concept towards the end of that article is a very good one,...somebody put a lot of good thought into that idea.

And since it looks like the speeds are going to be as great as the bigger boats, that shouldn't hurt things.

And each team gets to play around with different foils.

 

You can't possibly tell from that photo whether the rudders are setup for any particular attitude.

You have no idea of the camera or lens characteristics, no plane of reference, no idea of perspective or the angle the camera to the boat. You can't even see very much of the boat and the rudders are oblique to the axis of the photo. Most of all, you have no idea what angle is flat or bow up.

The difference between bow up and bow down is likely only a few degrees, you are dreaming if you think you can tell that by eye from a random image.

 

35th America's Cup on Foils---Oracle

You're very wrong. The rudder hydrofoil is obviously nose up and we know that because:
1) on an AC 45 the rudder foil can't be adjusted under sail,
2) the video and stills of that boat show it foiling with a pronounced nose down attitude,
3) the rudder hydrofoil would have to be in that position to allow a nose down attitude.

 

35th America's Cup on Foils! UK

Interesting shot by Lloyd Images of the BAR AC45's main foil. Much more curve than the other AC 45 foils I've seen:





A more typical AC 45 foil by Giles Martin-Raget:

 

35th America's Cup on Foils---Oracle-Tech Tuesday

Oracle Tech Tuesday video: https://www.youtube.com/watch?v=lb7m2DNsOsE


Commentary from www.catsailingnews.com on this video:

Video: Oracle Team USA - I like these tech series from Oracle, not much insights but well done informatives for all levels. This time more footage of the AC45 Turbo at Bermuda plus some CFD renders on a nice little clip. We don´t know about their latest foils, but those huge refined 'L' style daggerfoils (from first rough 'L' mainfoils used in their early AC45 /AC72 flights) keep catching my eye. Also in the video the nose down trim of the T45 is getting almost scary by now! (emphasis by DL)

 

35th America's Cup on Foils---Oracle

A sort of mini-tour of Oracles Bermuda headquarters:
https://www.youtube.com/watch?v=gDreCW1xl08

 

Thanks for snipping what you are replying to. What I said was:

So, specifically, what is wrong about my statements? You didn't even attempt to disprove a single one, you just say "you're wrong".

See above. Do you think these guys adjust the angle by eye?

You can't possibly tell what the rudders are set for definitively from a single image, you must have some frame of reference, such as an image taken with an identical camera, aspect and perspective of a foil that's "nose down" or in some known attitude for comparison.

So the image isn't proof of anything. You've seen a video and an image, supposed the two are correlated and come to a vague assumption. You don't even know if it's taken on the same day, before or after sailing, before or after the claimed "adjustment", or even of the same boat.

Even in the "bow down" video, there's no frame of reference for what constitutes up, down or flat or by how much.

The "bow down" image you posted seems to have the rudders on the opposite sides to the image of the boat on the hoist. On the water, the stripped rudder is to port and the "Yanmar" to starboard, whereas on the hoist they're the other way around. So one thing that can be said with certainty is that the rudder configuration is different between the two images.

 

The point is that you have no proof, absolutely none, that the rudders in the image are set to any particular configuration.

The point is that it's clear from the image that the rudders have been removed and replaced in the interval between the image and the video. So that means you can't possibly assume that the configuration is the same without some other evidence. The rudders may not even be in a configuration that's used for sailing at all.

You also know the boat has been setup to not be "bow down". So you can't know which configuration the rudders in the image are set to.

Probably…in my opinion…highly unlikely. All irrelevant opinion that has nothing to do with the image.

You've not provided one shred of evidence to support your statement. The onus is on you to prove its accuracy and you haven't.

 

Ha, Doug, exposed as a marching girl US cheer leader; maybe you'll stop your blatant and biassed silly, innacurate pimping/propaganda.
And maybe you won't?
Because it is your raison d'etre?

 

35th America's Cup on Foils---Oracle-nosedown attitude

On 17 it's obvious that the foils are set for a continuous nosedown attitude,the picture and various videos illustrate that 100%(posts 416, 423 and 425)*. Sorry you don't see it but it is completely clear to me. Nothing more needs to be said-the pictures and video back up the nosedown attitude and the setting required of the rudder foils for that attitude.
* See commentary from www.catsailingnews.com on the nosedown trim in post 425 above.

--The AC 45 rudders are ,likely, identical to each other-they'd have to be for any valid testing since they're both in the water at the same time. They could swap side to side with no problem-and they probably do just to be sure....
--They're probably trying to set "zero" for the 50's by setting up the ideal nosedown attitude now. The 50's will allow a three degree movement of the rudder foil(rake axis) so they'll want to be sure where "zero" is now. In my opinion, it's highly unlikely they'll try to use the windward rudder foil for "extra" RM, as some have suggested, because that will affect the pitch authority of the lee rudder foil.

 

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Geez, Gary-thats amazing!

 

35th America's Cup on Foils! TNZ

TNZ Capsizes in Chicago! https://www.tvnz.co.nz/one-news/spo...-in-practice-race-choppy-lake-michigan-waters
https://www.youtube.com/watch?v=eroYHwVuI8I

 

35th America's Cup on Foils---Oracle--Splashdown

Oracle went over Friday as well-no problems: https://www.youtube.com/watch?v=ww9yRwRlmbY

 

35th America's Cup on Foils! --Chicago ACWS

Imagine that: no wind in the windy city!! This is at least the third venue where there has been no wind this year for the ACWS.
UPDATE- one race got started and was won by TNZ, USA second.

 

35th America's Cup on Foils---Oracle + TNZ

Another perspective on yesterdays practice race between TNZ and Oracle-won by Oracle because TNZ capsized! This race may wind up counting.....
https://www.youtube.com/watch?v=I6AMsRbraFw