Emirates Team New Zealand.

weta27

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Thanks for the video, I was around the other side of North Head wondering where they were!

Looks like a bulbed foil on stbd, but in this they are only sailing on the port foil, so can't tell what type it is.

There wasn't much wind - glassy patches further out in Gulf.

 
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barfy

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3 hours ago, mikenz2 said:

They're under tow on the way back in now - someone run down to the viaduct and get the hi res photos :)

I only caught the last 15mins of their session today, wasn't paying attention out the window.
 

Closest approach to me at about 10 mins in


Nice! 

She goes right through the wake of one of the sister ferries at the end, probably a meter and a half face, with not a wiggle.

And what are they doing at bean rock? Dredging a channel between the light and the port hand?

 

barfy

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Could the “definitely not a camera” be looking at the intersection of the bulb/foil when it is immersed to see at what point there is flow separation and how it interacts with flap movement? 
That would be a reasonable study in a real test tank. Do you reckon you could see that viewing along a meter of wing? I've just seen tank footage from directly above in clear water. Although with the lack of rain the sea is pretty clear these days. Honest question for someone who has played with tanks.

 

JALhazmat

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That would be a reasonable study in a real test tank. Do you reckon you could see that viewing along a meter of wing? I've just seen tank footage from directly above in clear water. Although with the lack of rain the sea is pretty clear these days. Honest question for someone who has played with tanks.
Mine was an honest question from someone with no idea as never played with tanks.  No clue if it’s practical/feasible  but worth a guess? 
 

actually some of the drone heli shot of ineos when it first launched you could see flow/attaching detaching as the foil got close to the surface do maybe they can get something meaningful from underwater? 
 

still,  TC says they ain’t cameras so fuck it who knows! Lol 

 
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barfy

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Mine was an honest question from someone with no idea as never played with tanks.  No clue if it’s practical/feasible  but worth a guess? 
 

actually some of the drone heli shot of ineos when it first launched you could see flow/attaching detaching as the foil got close to the surface do maybe they can get something meaningful from underwater? 
 

still,  TC says they ain’t cameras so fuck it who knows! Lol 
That was my thought, the place to monitor the entire wing was from above, just where we saw the camera bulb on te aihe. Like you said, ventilation showed up from drones.but maybe some cavitation on the bottom surface that needs a look.

Fucking voodoo boats anyway.

 

RobG

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I just spent over 2 hours trying to find our discussion on foils where NZ was the outlier and all the other teams went with the bulb.  It must have been in the "old NZ" thread that was deleted.  I said that I thought NZ would eventually change over to the bulb foils.  The idea was that all of the other teams had already tested the bulb-less foils on their test boats and all of them decided independently to change to the bulb foils.  And all of the bulbs had the anhedral foils where as NZ started with one T-foils just like AM did on the Mule.   Most of the NZ posters said that I was missing the brilliant design of the NZ foils, I said that NZ was playing catch-up because they didn't have the "on the water" test boat experience of the other teams.
I posted some time ago an anecdote of a discussion with AMac circa 2015 (no idea how to find it) so I'll restate it. AMac's done his fair share of foil development and reckons bulbs are faster. Apparently he challenged some AC types  with their zillion dollar design and analysis packages to design a foil without a bulb that was faster than the same foil with a bulb. They couldn't do it. Asked why the bulb is faster, he just shrugged.

There are definite advantages to an anhedral foil when it's canted and the flaps are independent. The box rule for foils is clearly aimed at allowing anhedral shapes, I wonder what we'd see if the wings didn't need to be symmetrical.

 

RobG

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Interesting to see the bulb now on the port side foil, earlier pictures showed it only on the starboard side.  Either they switched sides, put bulbs on both foils or just flipped the picture.
Check the (barely visible) logo on the sail. Not flipped, unless someone took the time out to un–flip the logo.

 

RobG

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Can you quote [the rule about stuff on the tip] please?

We’ve seen ‘bulblets’ along other test foil-wings, and there’s been guesses that they house controls for the trailing flaps aligned with them. Might not these be controllable surfaces too, if that wing-tip part is ‘trailing’ as the other flaperons are?
The entire foil (which is everything attached to the bottom of the arm) has to fit in the box defined in fig. 13.1 (reproduced below), the appendage on the tip seems to go well outside the box.

The wings must be symmetrical about the junction with the arm (strictly the wing symmetry plane) so no special shapes on just one tip:

13.6 A foil wing must be symmetric about the foil wing symmetry plane, as defined in Figure 13.1, with a build tolerance of 3.0 mm, except that within 75 mm of the foil wing symmetry plane, non-structural fairings on the foil wing are not required to be symmetric.

fig 13.1 markep.png

 

Tornado-Cat

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We’ve seen ‘bulblets’ along other test foil-wings, and there’s been guesses that they house controls for the trailing flaps aligned with them. Might not these be controllable surfaces too, if that wing-tip part is ‘trailing’ as the other flaperons are?
Let's remind that rule:

13.6 A foil wing must be symmetric about the foil wing symmetry plane

 
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hoom

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On 5/19/2020 at 4:43 PM, mikenz2 said:

They're under tow on the way back in now - someone run down to the viaduct and get the hi res photos :)

I only caught the last 15mins of their session today, wasn't paying attention out the window.
 

Closest approach to me at about 10 mins in


Tow start after a rope thrown as it passed behind Bean Rock light?

But didn't look like a tow start after the closest point gybe & take-off acceleration was similarly rapid.

Perhaps noteworthy that they immediately throw the bulbed foil up on starboard but twin-foil on port, one could almost suspect they're trying to hide something :huh:

 




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