THE IMOCA thread, single/double handed & TOR

[minca3]

But at the end when high on the foils, he has the windward rudder lifted, so not clear if they want to use it as a rear "foil" or not, maybe for a further step...

Just speculating but: I think this high nose attitude is for action shots or generally to test the stall conditions of the foil.

A bit before you can see Charal 2 with the hull barely out of the water, and both rudders in the water. I assume this is the mode for which the rudder configuration has been designed for. As little angle of attack on the foil for minimum drag and as much of the windward rudder in the water for maximum flight control authority.

 

[RedFlag]

Just speculating but: I think this high nose attitude is for action shots or generally to test the stall conditions of the foil.

A bit before you can see Charal 2 with the hull barely out of the water, and both rudders in the water. I assume this is the mode for which the rudder configuration has been designed for. As little angle of attack on the foil for minimum drag and as much of the windward rudder in the water for maximum flight control authority.

Exactly

 

[huey 2]

New shots...

 

[terrafirma]

Awesome shots. Can't wait to see Charal in the Defi Azimut..! Against a stack of new boats and to see if these new boats have made ground on Apivia notwithstanding conditions. This new Manuard design is interesting, narrower than normal, rudder placement and scow bow make her an aggressive design for the up and coming races. Watching some of Charal's new video footage she seems to be able to fly steadily. There's no chance of that bow burying in a following sea.!

 

[Liquid]

RUDDER
(a) The number of rudders shall be 2.
(b) The “fully down” position of a rudder shall be its normal use position.
(c) The rudder in its “fully down” position shall be included in the hull length.
(d) In any other cases where the rudder is stable or fixed in position other than the “fully down” position, the CM shall be satisfied that the rudder has no effect on the flow of water on and near the hull shell.
(e) The rudder’s attachment points on the hull shall be permanently installed and remain in place.
(f) All points along the leading and trailing edge of the rudder shall be on the same plane.
(g) Below the hull shell, a fence may be fitted on each rudder to prevent localised ventilation. This fence shall be: (look up the rest yourself)

Way out on a limb...

Could one argue that the top bearing is permanently installed on the rudder post and remains in place at all times, like the bottom one?

Could I then articulate that permanently attached point (upper bearing) within a part that remains in place (rudder assembly), while in the "fully down" position?

 

[DickDastardly]

Just speculating but: I think this high nose attitude is for action shots or generally to test the stall conditions of the foil.

A bit before you can see Charal 2 with the hull barely out of the water, and both rudders in the water. I assume this is the mode for which the rudder configuration has been designed for. As little angle of attack on the foil for minimum drag and as much of the windward rudder in the water for maximum flight control authority.

It flies notably flatter than other IMOCAs. I'd imagine itv will have a much more effective and rapidly adjustable rudder toe in/out mechanism that essentially controls the levbel of vertical lift the two rudders are providing.

 

[Haligonian Winterr]

RUDDER
(a) The number of rudders shall be 2.
(b) The “fully down” position of a rudder shall be its normal use position.
(c) The rudder in its “fully down” position shall be included in the hull length.
(d) In any other cases where the rudder is stable or fixed in position other than the “fully down” position, the CM shall be satisfied that the rudder has no effect on the flow of water on and near the hull shell.
(e) The rudder’s attachment points on the hull shall be permanently installed and remain in place.
(f) All points along the leading and trailing edge of the rudder shall be on the same plane.
(g) Below the hull shell, a fence may be fitted on each rudder to prevent localised ventilation. This fence shall be: (look up the rest yourself)

Way out on a limb...

Could one argue that the top bearing is permanently installed on the rudder post and remains in place at all times, like the bottom one?

Could I then articulate that permanently attached point (upper bearing) within a part that remains in place (rudder assembly), while in the "fully down" position?

Only allowed one axis of movement in the rudder

 

[huey 2]

 

[Jethrow]

Only allowed one axis of movement in the rudder

But that axis is individual for each rudder right? Each rudder can be separately rotated/controlled/steered on it's one axis, not both rudders linked to a single control?

 

[yl75]

But that axis is individual for each rudder right? Each rudder can be separately rotated/controlled/steered on it's one axis, not both rudders linked to a single control?

Indeed, that's the trick

 

[yl75]

Interesting Verdier interview (probably auto translated though) :

3 questions for Guillaume Verdier “The architecture of the new IMOCAs is reminiscent of that of motor boats!”

With four boats launched this year (Biotherm, Holcim-PRB, Maître Coq, V&B-Mayenne-Monbana), the naval architect who designed APIVIA, LinkedOut and 11th Hour Racing Team is by far the most prolific on the IMOCA circuit. Crossing paths with him on the pontoons of Lorient La Base, Guillaume Verdier he…

www.defi-azimut.net

 

[DickDastardly]

But that axis is individual for each rudder right? Each rudder can be separately rotated/controlled/steered on it's one axis, not both rudders linked to a single control?

A toe-in/out control can alter the AoA of both rudders simultaneously to alter the amount of lift they generate while both are in the water, both rotating on their one axis.

 

[staysail]

Tracker software doing its usual thing. Everyone in the wrong place with ranking presumably being based on direct DTF rather that DTF allowing for the second turning mark!

 

[staysail]

Tracker software doing its usual thing. Everyone in the wrong place with ranking presumably being based on direct DTF rather that DTF allowing for the second turning mark!

Maybe they read my comment as now it seems to have been put right!

 

[wonderbrom]

Maybe they read my comment as now it seems to have been put right!

Keep up the good work

 

[minca3]

Insightful as always:

 

[[email protected]]

Insightful as always:

Thanks. That was really relatable.

 

[huey 2]

What a great team they are ...there is a Consensus just Incredible to see/hear them with all their new tech and they are comfortable with each other and learning their gear....so much to take in so try it and see..... to see the actual reality as to what the new tech is telling them
Comparing the information.... like establishing a Trust between the two worlds

 

[huey 2]

WRESTLING FOILERS!​

9/16/22

Tonight sees the two ‘Charlies’ still heading each group. American skipper Charlie Enright and his crew (11th Hour Racing Team) are leading the way after passing the Azimut 2 waypoint at 08:26 hours this Thursday morning, whilst Charlie Dalin, heading the fleet of solo sailors on APIVIA, followed suit one hour later.
Since then, the IMOCA skippers have been making headway at a slower, laborious pace, with the vast majority now launched onto a beat. The ETA for the front runners is from 06:00 local time tomorrow morning for the 23 solo sailors still out on the racetrack after Japanese skipper, Kojiro Shiraishi (DMG MORI Global One) retired last night for personal reasons. Signed up for a longer course, which will take them on a slight detour via Penmarc'h, the four crews are due to make the finish from noon.
As promised, this ‘48 Heures’ race in the Défi Azimut-Lorient Agglomération began with a long downwind sprint with the competitors reaching the first mark at quite a lick after an exhilarating run. This was also true for those sailing their boats in race mode for the first time, like Samantha Davies, aboard her brand-new scarlet red Initiatives Cœur. “The sunset, an average speed of 26-27 knots… It was incredible! With Justine (Mettraux) only just behind me, and within sight of several boats, the drop down to the first mark was really nice,” explains the sailor, despite having to contend with water ingress aft, not far from the batteries for the electronics. Fortunately, it was more of a fright than anything and tonight she’s positioned in 7th place less than 30 miles from the head of the fleet.
“The first 24 hours were pretty steady on a long stretch of downwind with a gybe that was difficult to time right. We knew that APIVIA’s used to sailing above her polars (speed estimates according to the conditions and points of sail), but there were lots of boats able to match that,” commented Hubert Lemonnier, Race Director. “The foilers clearly have the edge,” he adds.
This evening, the hierarchy established on the water illustrates this gradual takeover, after a race start that saw a small group of boats with daggerboards able to keep pace downwind under spinnaker focused on VMG.
Following the stretch of reaching in what was a shifty breeze both in terms of strength and direction between the waypoints of Azimut 1 and Azimut 2, the wrestling match between the leading foilers reached fever pitch as the first boats launched onto a beat for home. It’s achingly close tonight between the unshakeable APIVIA (Charlie Dalin) and LinkedOut (Thomas Ruyant), who are bunched within a handful of miles as per usual. However, the newbies can’t be discounted either: Charal (Jérémie Beyou), and V and B-Monbana-Mayenne (Maxime Sorel) are poised to pounce just astern of them. It’s the same for Holcim - PRB (Kevin Escoffier), who’s made a fantastic comeback in the second wave. All of them have really been able to show what they’re made of out on the racetrack with peak speeds of between 29 and 34 knots overnight. All this merry band are making headway within ten miles of one another with less than 150 miles to the finish.
On the tally of great performances, it’s essential to mention that of Monnoyeur-Duo for a job (Benjamin Ferré), the first boat with daggerboards, which is hanging onto 8th place. Mission accomplished for the skipper who said this morning: “We’ve put on our finest speed goggles! I’ve just passed the Azimut 2 mark and after a slight tac-tac to reposition myself, I’ll launch onto a beat and try to catch my mate Attanasio. All’s well aboard!” This afternoon, he’s really holding his own ahead of several foilers, with Fortinet-Best Western (Romain Attanasio) and Groupe APICIL (Damien Seguin), as his closest rivals. Gentoo Sailing Team (James Harayda) is also sending it, despite being new to the circuit and has been well positioned since the start of the race.

At 17:30 hours, Ollie Heer Ocean Racing (Ollie Heer) and freelance.com (Guirec Soudée), in 20th and 21st positions respectively, had just passed the Azimut 2 mark, so they too are now embroiled on a beat to the finish offshore of Lorient. “Upwind always involves twice the distance and three times the pain”, according to offshore racing lore, particularly at the back of the fleet where there’s a risk that the front runners will extend away…

 

[Raptorsailor]

Given the mad rush to make the foils bigger than most wings of small aircraft, I would have thought the trend on this coming generation of IMOCA would be to make the hull as thin as possible.... same goes for the cockpit design of the Charal 2. But then again, I'm sure the architects and sailors have their reasons.