Foils for offshore racing

DFL1010

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And from their twitter:

"la vidéo sera disponible demain matin mais les images méritent un peu de patience... "

Roll on tomorrow!
This pic just takes the Mick though:
11953566_700351890094784_4205492716252128085_o.jpg




Between the scow bow and the foils, they're really optimising for the strong stuff, as shown by a non-spectacular performance in the Fastnet.

Interesting wee vid showing the build, and an interview with Sébastien Josse (FR), that deals with the expected gain/loss.

 

Roberto

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The designers VPLP explained that according to new Imoca rules, the canting keel provides a dynamic *heeling* moment -the canted blade is at an angle to the water- (plus of course the static righting moment given by the bulb), this keel heeling moment is balanced by the foil, which also provides the antidrift component; the boat has thus two lifting surfaces (the keel fin and the foil) which contributes to give it more power and somewhat make it sail "less heavily".


This is another one of these new Imoca foilers, my pictures so a lot less artistic :D





 

Roberto

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Woodlouse

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I wouldn't want to raft up outside it.
No? They do retract you know. The pics I've seen have them with lovely big soft pads covering them too so no need for fenders!

It's a seriously cool step though as far as open 60's go. I've not noticed it done on the mini transats though which is a bit odd, they tend to be a bit of a test bed for innovation like this.
 

temptress

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Foolish Muse

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Fantastic article about the IMOCA 60 foils here: http://www.sailingworld.com/new-generation-imoca
You should all read it.
When I interviewed boat designers for my singlehanded tips book two years ago, I learned all about the use of the dagger boards for making the boat move straight through the water "like a dart", rather than crabbing sideways like most of our boats do. And I also learned all about the DSS foils sticking out the side of the boat. When the new Dali foils came out, I just assumed that the large, main part of the foil acted as the dagger board to keep the boat straight in the water. But I was wrong. According to the article, it is the tip of the foil, the part outside of the elbow bend, that is the dagger board keeping the boat straight in the water. Likewise, it is the actual elbow of the U that is lifting the boat up. Very interesting indeed.
 

Foolish Muse

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Fascinating. Thanks for that. I wonder what they're going to do with that shaft? With the canted keel giving lift the wrong way and the foil shaft causing problems. It will be great to see what they come up with next.

I just want my own little boat with twin rudders, canting keel, twin dagger boards and twin DSS foils. Nothing much at all on a 30 footer, and just a few lines for a singlehander to manage :)
 

Buck Turgidson

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Much more in depth (and therefore to me interesting) is this talk from the summer:


Interesting set of presentations. Particularly the Rave V. Not for the boat but because it's the first time I've heard someone talk about supercritical airfoils in this application. I use them everyday, but I'm traveling in the transonic regime at 30-40 thousand feet but as the guy says, the R number is in the same ball park.
Lifting tubes is something else that's very interesting and I'm pretty sure we will see foils going that way in the next few years.
Next I want to hear someone talk about area ruling hulls.
 
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