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sarah0809

Artemis?

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Nice one

 

 

Published on Dec 14, 2012

 

We have had a couple of excellent days out on the water and our knowledge of the boat has increased tremendously. Here is our latest update on the State of the Artemis. Enjoy!

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monitor3.jpgmonitor4s.jpg

These are two images of the control system of Monitor, a famous early hydrofoil sailboat.

You cannot see it very clearly in the aft end shot, but there is a linkage between the standing backstay and the stern foil, such that if the rig blows forward, the angle of the stern foil changes to trim the bow up.

The first picture shows the shroud attachment , which is on a torsion spring, linked to the main foils. Once again change the load on the shroud, change the angle of attack on the foils. In both cases, the attempt is to use springs and elasticity of structure to control flight.

These mechanisms are detailed in the patents that Baker took out on the boat.

The twisting of the Oracle platform may have been an attempt to do the same thing. It isn't an unreasonable design path, one with some precedent and at least some history of success for managing "wand free" foiling.

Assume you grossly trim the vessel for level flight using the leeward daggerboard foil and rudder foil. You would then like something like a fine tune response. On a Moth you trim the ship with the twist grip on the rudder and then the wand on the daggerboard does the fine tuning. On Oracle you would trim with the weather rudder flying out of the water and then sail with the rudder responding to the through the spring of the platform. In the Moth, a great deal is made of the amount of buffering necessary with the wand, bungee strength, wand spring and size of the paddle are all fussed with. Oracle was on Day 6 of a much bigger tuning problem when they crashed. I don't know this, but it doesn't seem like an inherently flawed flawed approach to the problem. So, no I don't think the stiffest possible platform is an essential precondition to building a successful foiling catamaran. Having a platform that distorts in a predictable way, is pretty key, but there is little coming from Oracle saying that the platform was distorting in ways they did not anticipate.

 

I think Artemis was blind sided by PI22. The rules were pretty clearly written to prevent full hydrofoiling, and the reversal of the measurement committee's interpretation certainly changed the balance of the fly no fly equation. As a result Artemis may not have the high end speed potential that ETNZ has been flashing around. This doesn't necessarily mean they are doomed. These are short races in an artificially confined course area. How the boat accelerates out of a tack or gybe may be more important than how fast they can go for 1:30 seconds in between the tacks and gybes.

The double slotted wing may have a big impact here. If flow attaches 5 seconds earlier than on a single slotted wing and the boat can light up before the gennaker is sheeted all the way in, they may be impossible to put away. I haven't done the studies or seen them, but these are questions you need to answer if you are designing for a certain type of race. It may be interesting that while ETNZ seems to have been happy joy riding at high speed, Loic has the Artemis team doing starting drills and bearaways. In effect focusing on RACING the boat not just sailing it. That could be seen as acknowledgement that being really slick at the boat handling is the only shot they have, but I think it is more likely an assertion that short course racing is actually the game here and that high performance boats demand a higher level of maneuvering reliability to succeed.

 

I have been beaten too many times by boats that looked less elegant and sophisticated than mine to be much upset by a few gaps in the trailing edge of the Artemis wing. The picture of the Trimaran looks like they are trying to get back to the beach with a bunch of things going wrong.

 

It is really hard to make any predictions about the relative performance of these boats without seeing them side by side. When Fredo built Rocker, if you looked at the pictures you would have thought those of us sailing in the water would be doomed. Which was completely not the case. So all of us have to be aware that our preconceptions can be very misleading. I'm not an apologist or fan for any team. I think these are complicated issues. People making snap judgements and defamatory statements about the people who are actually doing the work and taking the risks pisses me off.

SHC

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" It may be interesting that while ETNZ seems to have been happy joy riding at high speed, Loic has the Artemis team doing starting drills and bearaways. In effect focusing on RACING the boat not just sailing it. That could be seen as acknowledgement that being really slick at the boat handling is the only shot they have, but I think it is more likely an assertion that short course racing is actually the game here and that high performance boats demand a higher level of maneuvering reliability to succeed."

 

Steve, with the greatest respect you know ETNZ has been doing more than showing off joy riding at high speed, they have been doing all that which Artemis have been doing plus racing against an actual other AC72

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Steve

 

FWIW, your analysis is exactly what I have tried to say on this forum for ages, so tyhnaks for coming on here and posting. I don’t think the ETNZ fanboys will like the message. For me, the AR wing is a really clever bit of kit and while you rightly point out that it doesn't look pretty, I believe it really could be a game changer. Nobody can say with any certainty that it will be or not, but I bet the aero guys in other teams are just as worried about it as the hydro guys are about the ETNZ foils.

 

The other point about racking that people don't seem to get is that the key hull in regard to foiling is the leeward hull and its relationship to the foils. Racking does not change the leeward foils at all. It only effects the windward ones and if you sail with the windward hull and foils out, flex doesn't effect the foils one bit.

 

So all of us have to be aware that our preconceptions can be very misleading. I'm not an apologist or fan for any team. I think these are complicated issues. People making snap judgements and defamatory statements about the people who are actually doing the work and taking the risks pisses me off.
I hope you don't get the same level of abuse as I have got for expressing exactly the same view as this, but you are so spot on. But i guess that is SA for you. Never let the facts and reality get in the way of a good forum fight!

 

For sailors of development cats, this is one of the most exciting times ever. We might get answers to some very interesting questions that have been out there for a long time and I think we will see some trickle down benefit for multis in general. Fun times!

 

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Steve

 

FWIW, your analysis is exactly what I have tried to say on this forum for ages, so tyhnaks for coming on here and posting. I don’t think the ETNZ fanboys will like the message. For me, the AR wing is a really clever bit of kit and while you rightly point out that it doesn't look pretty, I believe it really could be a game changer. Nobody can say with any certainty that it will be or not, but I bet the aero guys in other teams are just as worried about it as the hydro guys are about the ETNZ foils.

 

Personally I doubt this Simon - they haven't got much else right yet have they? And despite your claim of justification, all Steve said was there might be some advantage to AR 'double slot'. You have picked on the slightest thing with ETNZ to criticize, that's one of the reasons I pointed out the very un-aerodynamic flaps on AR, but you are quite happy to dismiss this or even claim it as an advantage?! They can do no wrong apparently - a bit like Alinghi in the last event eh! :lol:

 

The other point about racking that people don't seem to get is that the key hull in regard to foiling is the leeward hull and its relationship to the foils. Racking does not change the leeward foils at all. It only effects the windward ones and if you sail with the windward hull and foils out, flex doesn't effect the foils one bit.

 

I at least was careful to point out the detrimental affect was to the windward foils and that's been discussed here for months - but go ahead with your 'people don't get' and 'No one here understands'. Try reading other than to look for someone who backs up your latest theory.

 

So all of us have to be aware that our preconceptions can be very misleading. I'm not an apologist or fan for any team. I think these are complicated issues. People making snap judgements and defamatory statements about the people who are actually doing the work and taking the risks pisses me off.
I hope you don't get the same level of abuse as I have got for expressing exactly the same view as this, but you are so spot on. But i guess that is SA for you. Never let the facts and reality get in the way of a good forum fight!

 

For sailors of development cats, this is one of the most exciting times ever. We might get answers to some very interesting questions that have been out there for a long time and I think we will see some trickle down benefit for multis in general. Fun times!

 

Oh please!

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As has been commented, the rig may be the key to this regatta, but surely you guys noticed what was happening with the rig when OR72 was twisting and fluttering?

I agree that as long as the windward hull is out of the water, it can twist all it likes, but not when you see the forestay flopping in and out of tension causing the jib to be under then over-sheeted, the wing wobbling back and forward rake in-rake out, and the windward hull alternately touching bow, then stern.

That is not automatic trimming - that is a trimmers nightmare!

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Nice one

 

 

Published on Dec 14, 2012

 

We have had a couple of excellent days out on the water and our knowledge of the boat has increased tremendously. Here is our latest update on the State of the Artemis. Enjoy!

 

Haha, Loick is awesome!

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The other point about racking that people don't seem to get is that the key hull in regard to foiling is the leeward hull and its relationship to the foils. Racking does not change the leeward foils at all. It only effects the windward ones and if you sail with the windward hull and foils out, flex doesn't effect the foils one bit.

 

 

Look at 3:30 in this video:

It might not be "racking" but almost all action is going at the leeward hull.

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Steve

 

FWIW, your analysis is exactly what I have tried to say on this forum for ages, so tyhnaks for coming on here and posting. I don’t think the ETNZ fanboys will like the message. For me, the AR wing is a really clever bit of kit and while you rightly point out that it doesn't look pretty, I believe it really could be a game changer. Nobody can say with any certainty that it will be or not, but I bet the aero guys in other teams are just as worried about it as the hydro guys are about the ETNZ foils.

 

Personally I doubt this Simon - they haven't got much else right yet have they? And despite your claim of justification, all Steve said was there might be some advantage to AR 'double slot'. You have picked on the slightest thing with ETNZ to criticize, that's one of the reasons I pointed out the very un-aerodynamic flaps on AR, but you are quite happy to dismiss this or even claim it as an advantage?! They can do no wrong apparently - a bit like Alinghi in the last event eh! :lol:So, Nav, when Steve says the AR wing is interesting and has some real potential, you don't argue. When i support that view, you do? I am beginning to think you are simply trolling. To quote Steve "The double slotted wing may have a big impact here. If flow attaches 5 seconds earlier than on a single slotted wing and the boat can light up before the gennaker is sheeted all the way in, they may be impossible to put away".

 

The other point about racking that people don't seem to get is that the key hull in regard to foiling is the leeward hull and its relationship to the foils. Racking does not change the leeward foils at all. It only effects the windward ones and if you sail with the windward hull and foils out, flex doesn't effect the foils one bit.

 

I at least was careful to point out the detrimental affect was to the windward foils and that's been discussed here for months - but go ahead with your 'people don't get' and 'No one here understands'. Try reading other than to look for someone who backs up your latest theory.Since when did "people" mean everybody. If you have been one of the few saying it, fine, then "people" doesn't include you. Also say that it is my latest theory is doing exactly what you accuse me of doing, not reading what I have said because I said it from day 1, based on the work I have been doing on in the A's. Again, you seem to want to pick a fight for the sake of it

 

So all of us have to be aware that our preconceptions can be very misleading. I'm not an apologist or fan for any team. I think these are complicated issues. People making snap judgements and defamatory statements about the people who are actually doing the work and taking the risks pisses me off.
I hope you don't get the same level of abuse as I have got for expressing exactly the same view as this, but you are so spot on. But i guess that is SA for you. Never let the facts and reality get in the way of a good forum fight!

 

For sailors of development cats, this is one of the most exciting times ever. We might get answers to some very interesting questions that have been out there for a long time and I think we will see some trickle down benefit for multis in general. Fun times!

 

Oh please! Maybe you will never get it. I spent a fair biut of yesterday worjing with a multi world champion A Class sailor looking at exactly what foils we are going to build next week and much of the work was comparing what the AC guys are doing vs what our rules allow. We believe that the gear we will be using at the next worlds will be different from what was used at the last one and that what is going on at the moment is a 2 way flow of ideas between the small development cats - A's and C's - and the AC. If playing around in this space isn't fun (if that's what you are into), then I don't know what is

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Simon, read Steves answer to my question in the Oracle thread. Backs up what I have been saying about the windward rudder 100%.

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Simon, read Steves answer to my question in the Oracle thread. Backs up what I have been saying about the windward rudder 100%.

Doug

 

We are talking about the wing here!

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Steve

 

FWIW, your analysis is exactly what I have tried to say on this forum for ages, so tyhnaks for coming on here and posting. I don’t think the ETNZ fanboys will like the message. For me, the AR wing is a really clever bit of kit and while you rightly point out that it doesn't look pretty, I believe it really could be a game changer. Nobody can say with any certainty that it will be or not, but I bet the aero guys in other teams are just as worried about it as the hydro guys are about the ETNZ foils.

 

The other point about racking that people don't seem to get is that the key hull in regard to foiling is the leeward hull and its relationship to the foils. Racking does not change the leeward foils at all. It only effects the windward ones and if you sail with the windward hull and foils out, flex doesn't effect the foils one bit.

 

So all of us have to be aware that our preconceptions can be very misleading. I'm not an apologist or fan for any team. I think these are complicated issues. People making snap judgements and defamatory statements about the people who are actually doing the work and taking the risks pisses me off.
I hope you don't get the same level of abuse as I have got for expressing exactly the same view as this, but you are so spot on. But i guess that is SA for you. Never let the facts and reality get in the way of a good forum fight!

 

For sailors of development cats, this is one of the most exciting times ever. We might get answers to some very interesting questions that have been out there for a long time and I think we will see some trickle down benefit for multis in general. Fun times!

 

 

===================

Coulda fooled me, ace.............

 

We are talking about the wing here!

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Whatever, Doug. While you continue to play with your silly models and speculate on the net, I will continue to sail and do it for real. I'm off to test a new set of foils :D

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Whatever, Doug. While you continue to play with your silly models and speculate on the net, I will continue to sail and do it for real. I'm off to test a new set of foils :D

===================

What a petulent, pathetic comment! You've sunk to a new low. And all that because? Oh yeah, I know: just because you might be dead wrong you lash out at anyone who disagrees.....Just plain pitiful ,Simon.

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Whatever, Doug. While you continue to play with your silly models and speculate on the net, I will continue to sail and do it for real. I'm off to test a new set of foils :D/>
=================== What a petulent, pathetic comment! You've sunk to a new low. And all that because? Oh yeah, I know: just because you might be dead wrong you lash out at anyone who disagrees.....Just plain pitiful ,Simon.

 

 

Not pathetic. Just from one who does...

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Love Loick but everyone needs to remember the South Bay is FLAT. Calm. A great training ground but really training wheels environment compared to the central bay.

 

Respect Artemis, but comparing this ebb condition to the oracle flip date is a huge stretch. Oracle flip date was a max ebb with Big Westerly and huge descending puffs. This weeks weather has been benign. Yes, big ebb, but not the associated big wind that makes it ugly.

 

Keep pushing Artie. Great effort these days.

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The twisting of the Oracle platform may have been an attempt to do the same thing. It isn't an unreasonable design path, one with some precedent and at least some history of success for managing "wand free" foiling.

Assume you grossly trim the vessel for level flight using the leeward daggerboard foil and rudder foil. You would then like something like a fine tune response. On a Moth you trim the ship with the twist grip on the rudder and then the wand on the daggerboard does the fine tuning. On Oracle you would trim with the weather rudder flying out of the water and then sail with the rudder responding to the through the spring of the platform.

 

Sorry but I've read this a few times and still don't understand it, perhaps because this is all quite new to me. I think you are suggesting that twist (racking) of the windward canoe body is being used to trim the leeward daggerboard and rudder. I don't understand the mechanism you are proposing that links the two?

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Nice one

 

 

Published on Dec 14, 2012

 

We have had a couple of excellent days out on the water and our knowledge of the boat has increased tremendously. Here is our latest update on the State of the Artemis. Enjoy!

 

You've got to love the spark and enthusiasm Loick brings to the team, crystallizing everyone, not to mention his vast multihull experience.

 

Wasn't it just about a week ago that ta koodie was predicting the demise of the team because of the changes ?

 

Of course he always preys on these types of things.

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The link is the beams themselves.

As the windward hull changes angle relative to the leeward hull, the angle of attack of the windward t foil changes.

This varies the amount of vertical force the weather rudder t foil generates relative to the leeward t foil.

This feeds back into the platform and effects the trim of the entire platform.

How quickly it has an effect depends on the rigidity of the system, and a flexible platform will have the effect of dampening or modulating the variations. In the foilers with surface sensing wands, the dampening is one of the key tuning variables, so I am suggesting that this was part of the Oracle design.

 

There is a simpler option: Assume you are running the leeward T foil at some positive angle of attack, like 3-5 degrees. ( I14s run +7 so it's not out of the range of possibilities) If you wanted to wash out the windward T foil so that it was running at a lower angle of attack ( which would be less draggy and make it exit and reenter waves with less fuss) you might be happy to let the windward hull trim bow down to achieve this.

SHC

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It sure is fun reading all this foiling theory on a thread about a boat that was apparently not designed to foil.

Maybe foiling needs its own thread

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The link is the beams themselves.

As the windward hull changes angle relative to the leeward hull, the angle of attack of the windward t foil changes.

This varies the amount of vertical force the weather rudder t foil generates relative to the leeward t foil.

This feeds back into the platform and effects the trim of the entire platform.

How quickly it has an effect depends on the rigidity of the system, and a flexible platform will have the effect of dampening or modulating the variations. In the foilers with surface sensing wands, the dampening is one of the key tuning variables, so I am suggesting that this was part of the Oracle design.

 

There is a simpler option: Assume you are running the leeward T foil at some positive angle of attack, like 3-5 degrees. ( I14s run +7 so it's not out of the range of possibilities) If you wanted to wash out the windward T foil so that it was running at a lower angle of attack ( which would be less draggy and make it exit and reenter waves with less fuss) you might be happy to let the windward hull trim bow down to achieve this.

SHC

So what's happening in this picture?

CC121001-503.jpg

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That isn't a good look.

Clearly the windward hull has taken a much greater bow down attitude than is desirable and the weather rudder T fil has fully ventilated and id making nothing but spray.

But it doesn't mean that the boat is worthless either.

 

It may not be as simple as tightening a few turnbuckles to restrict the rotation of the windward hull, but it might not be a whole lot harder. You don't know and neither do I .

I'm not saying it is perfect, but I am saying that there is a rational reason for why one might try to build a boat that was "not as stiff" as many might expect. That reason s could very well be the restrictions on the foiling controls.

I have no skin in the game, so I am willing to continue to observe and see what happens. I don't get any points for picking the winner, so why should I try?

SHC

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yes, some good inner views

 

Cayard wrote in an email. "Further, no one knows if AC72s will be able to effectively match race midsummer in SF Bay. They are seriously overpowered boats. For these reasons, we have shifted our strategy and added a complement of experienced multihull and skiff sailors in Loick Peyron and Nathan Outteridge, to helm the boat."

 

which tends to suggest they now see the races as being speed races

 

not match races

 

and so much so

 

that they sacked their top match racer as being redundant

 

they may often disagree with GD publicly

 

but their actions tend to suggest that they privately agree

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Only match racing I've seen on the 72's is PRADENZ.

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Cayard wrote in an email. "Further, no one knows if AC72s will be able to effectively match race midsummer in SF Bay. They are seriously overpowered boats. For these reasons, we have shifted our strategy and added a complement of experienced multihull and skiff sailors.

 

Are you kidding me? How could anyone with half a brain thenk that a "Match Racer" would be a better helmsman than a "Complement of Experoienced Multihull Sailors"

 

Even the starts are all going to be about speed. Having the ability to find a few knots of boatspeed, just because you're so good will be such an advantage.

 

You can also tell by the set up that the boat is set up for this "Match Racing" mode.

 

When boats are going 35 kts, who ever tacks one more time than the other guy in a race will lose. There will not be tacking duels or covering. it's all about finding the velocity and exploiting it with some tactical bitsthrown in.

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The double slotted wing may have a big impact here. If flow attaches 5 seconds earlier than on a single slotted wing and the boat can light up before the gennaker is sheeted all the way in, they may be impossible to put away. I haven't done the studies or seen them, but these are questions you need to answer if you are designing for a certain type of race. It may be interesting that while ETNZ seems to have been happy joy riding at high speed, Loic has the Artemis team doing starting drills and bearaways. In effect focusing on RACING the boat not just sailing it. That could be seen as acknowledgement that being really slick at the boat handling is the only shot they have, but I think it is more likely an assertion that short course racing is actually the game here and that high performance boats demand a higher level of maneuvering reliability to succeed.

 

 

 

 

Is their wing actually double slotted (3 element) of are the flaps on the front element split on the vertical for-aft plane with their own hinge points (very much like having the plane spoiler on each side of the wing), maybe with their trailing edges even joined with some sort of sliding arrangement?

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^^

 

Stimulating thought, just what is needed :) . Except:

 

- as Basiliscus pointed out, an extended spoiler would likely exceed the 1.85% (??) half-girth increase

- external surfaces are distinctly rounded. And mainly

- there's always the unexplained air gap

 

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^ good piece there

 

Not really!

 

Says nothing!

 

The only new bit is the fact TH is mates with Jobson.

 

And they have talked through the situation.

 

In fact, this is a very lazy (and uninteresting) bit of journalism.

 

Would be interesting to hear what KJ thinks.

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^^

 

Stimulating thought, just what is needed :) . Except:

 

- as Basiliscus pointed out, an extended spoiler would likely exceed the 1.85% (??) half-girth increase

- external surfaces are distinctly rounded. And mainly

- there's always the unexplained air gap

 

This was my thinking:

post-17365-0-20206500-1355699051_thumb.jpg

 

post-17365-0-77097200-1355699066_thumb.jpg

 

post-17365-0-51195400-1355699086_thumb.jpg

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Yes we went through that discussion before.

 

I think it must be a V shape open on the front.

Somehow for some reason they have made no attempt to fair in the leading edge other than a membrane in the gap somewhere.

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I'm guessing the leading edge of the intermediate fairing has a larger radius than the thickness of the trailing edge of the main wing. This helps to keep air attached when deflected. Aerobatic airplanes have been doing this for years.

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43c21d58cd6d673c516f0e9c93fa6e48.jpg

 

Hadnt seen that picture, definitely not what I guessed at

 

that just looks heavy to me

 

the whole wing in comparison to the etnz and or designs it looks a lot heavier

 

i wonder if it's overweight and part of the reason the ar platform looks to be sitting too deep in the water?

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^ good piece there

 

Not really!

 

Says nothing!

 

The only new bit is the fact TH is mates with Jobson.

 

And they have talked through the situation.

 

In fact, this is a very lazy (and uninteresting) bit of journalism.

 

Would be interesting to hear what KJ thinks.

 

Why does everyone here have to use two initials for a persons name? Who is kj Karl jones? Other than that Hastings you are just a jerk who hates everything about America, go do your black heart thing somewhere else.

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Hastings you are just a jerk who hates everything about America, go do your black heart thing somewhere else.

 

You will be happy to know that, with the exception of passing through US airports (and the occasional dtrop-in on 2nd hand book shops - eg. Powells - and used boat-bit places) I am already following your elegant instructions.

 

I can assure you it ain't just me.

 

These days many, many people living "somewhere else" put a lot of energy into avoiding the US of A.

 

Best to leave the Excited States to erudite souls who think they inhabit the centre of the universe.

 

 

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43c21d58cd6d673c516f0e9c93fa6e48.jpg

 

Hadnt seen that picture, definitely not what I guessed at

 

that just looks heavy to me

 

the whole wing in comparison to the etnz and or designs it looks a lot heavier

 

i wonder if it's overweight and part of the reason the ar platform looks to be sitting too deep in the water?

 

How about now?

34orjfq.jpg

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The wing is the monster making AR a submarine.

Wow, just wow. Your insight is simply amazing.

 

What brilliant deduction brought you to that conclusion ??

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Hastings you are just a jerk who hates everything about America, go do your black heart thing somewhere else.

 

You will be happy to know that, with the exception of passing through US airports (and the occasional dtrop-in on 2nd hand book shops - eg. Powells - and used boat-bit places) I am already following your elegant instructions.

 

I can assure you it ain't just me.

 

 

But if it is only you, I can assure you we are very happy.

 

Please park your tent somewhere else outside of the US - it will please many.

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that just looks heavy to me

 

the whole wing in comparison to the etnz and or designs it looks a lot heavier

 

i wonder if it's overweight and part of the reason the ar platform looks to be sitting too deep in the water?

 

et tu, erice?

 

Repeat after me: the sailing weight of an AC72 is fixed within 200 kg

 

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that just looks heavy to me

 

the whole wing in comparison to the etnz and or designs it looks a lot heavier

 

i wonder if it's overweight and part of the reason the ar platform looks to be sitting too deep in the water?

 

et tu, erice?

 

Repeat after me: the sailing weight of an AC72 is fixed within 200 kg

That's right but has it been measured yet ? .. If not measured they can use it as a surrogate

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i had thought the wing was measured separately

 

and not part of the sailing weight

 

but i stand corrected by our more knowledgeable italian anarchisti

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i had thought the wing was measured separately

 

and not part of the sailing weight

 

but i stand corrected by our more knowledgeable italian anarchisti

Class Rule 10.12 The weight of the wing in wing measurement condition shall be not less than 1325 kg,

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I'm guessing the leading edge of the intermediate fairing has a larger radius than the thickness of the trailing edge of the main wing. This helps to keep air attached when deflected. Aerobatic airplanes have been doing this for years.

 

Why didn't you tell that sooner, instead of standing by sadistically as I was eating crow over AR's supposed three-element wing?

 

In fact, a simple search for aerobatic airplane ailerons yields:

 

What good is 2-D analysis on idealized airfoils if you are gonna chop the back 30% off and install an aileron with big gaps in it's place.  The typical aerobatic aileron is symmetrical or almost nearly so.  At full difflection, the nose pops up into the flow on the opposite side of the wing.  The gap will be relatively small in at full diflection and the flow will first cross the gap, then accelerate out around the curvature of the nose before being turned to follow the aileron surface.  It makes for the lowest radius turn possible and improves the chances that the flow stays attached.  Also, the ailerons are slightly thicker than the wing at the cutout.  This encourages the flow to reattach after jumping the gap (helps when there is little or no aileron diflection).

 

Can we consider the matter settled now?

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Had it on the web cam, but just lots control. They were behind Alcatraz, maybe coming up to the race track?

http://207.150.197.186

They're coming!

If you're using the cam, try using the arrow keys on your keyboard it's much smoother than mouse control.

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Had it on the web cam, but just lots control. They were behind Alcatraz, maybe coming up to the race track?

http://207.150.197.186

They're coming!

If you're using the cam, try using the arrow keys on your keyboard it's much smoother than mouse control.

 

nice tip. what's the keyboard shortcut for zoom in/out?

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Had it on the web cam, but just lots control. They were behind Alcatraz, maybe coming up to the race track?

http://207.150.197.186

They're coming!

If you're using the cam, try using the arrow keys on your keyboard it's much smoother than mouse control.

 

nice tip. what's the keyboard shortcut for zoom in/out?

Don't know haven't found it yet, it would be useful though.

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Had it on the web cam, but just lots control. They were behind Alcatraz, maybe coming up to the race track?

http://207.150.197.186

They're coming!

If you're using the cam, try using the arrow keys on your keyboard it's much smoother than mouse control.

 

nice tip. what's the keyboard shortcut for zoom in/out?

Don't know haven't found it yet, it would be useful though.

If you click on the picture it centers on the mouse click.

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Had it on the web cam, but just lots control. They were behind Alcatraz, maybe coming up to the race track?

http://207.150.197.186

They're coming!

If you're using the cam, try using the arrow keys on your keyboard it's much smoother than mouse control.

 

nice tip. what's the keyboard shortcut for zoom in/out?

+ & - key on keypad

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Fun chart here showing Sailing Days

 

http://www.cupinfo.c...ing-days-01.php

 

Cool - thanks. Was thinking about making the same chart over the weekend but that task quickly went to the back burner.

Yes it is cool, let's hope they keep it updated. One clear trend so far is how fast a ramp-up LR has had, which figures of course but still.

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I think the slow mono is passing them :D

 

Wow!

 

post-20594-0-84462000-1355779334_thumb.jpg post-20594-0-40326400-1355779336_thumb.jpg

That are the two best shots of AC 34 Rennie !!!! A plastic bathtub passing an AC72 !!!!

 

Congrats, you were quick !

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FYI

 

 

===============

Thanks for that video! Some of the shots show the lee bow lifted quite a bit-and with the lee board still up a ways. Will be interesting in more wind with the board all the way down and the top canted to leeward(if it cants).

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One think about Artemis that I do like is the way the windward board retracts almost completely, ETNZ is pretty ugly with the windward board kissing the waves, very messy! Artemis you hardly even notice when it touches down.

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+1. For the freeze games too, Rennie.

 

When I had a chance to watch earlier they threw several quick maneuvers in, in pretty short order. Light airs but they looked fairly nifty.

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One think about Artemis that I do like is the way the windward board retracts almost completely, ETNZ is pretty ugly with the windward board kissing the waves, very messy! Artemis you hardly even notice when it touches down.

The retracted ETNZ foil kicks the windward hull back up into the air when it drops onto the surface while foiling...no accident I suspect

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White caps out there...

 

post-20594-0-57038700-1355785723_thumb.jpg post-20594-0-05085300-1355785725_thumb.jpg

====================

The lee daggerboard is still part way up for some reason. The configuration of that foil will produce more vertical lift all the way down, esp. if the top of the board cants to leeward. We'll see....

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where's she at??? good cam driving until she went far to the right and disappeared behind the club. nice views while it lasted though.

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where's she at??? good cam driving until she went far to the right and disappeared behind the club. nice views while it lasted though.

They've been heading down wind then back up behind Alcatraz, when they're at the furthest point they're kind of hard to see on the cam. Also they're probably close to heading home for the day.

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Are they only training in light wind ? :wacko:/>

 

Lake Hauraki??

Why not?

 

Everyone who is squint-eyed knows that the wind limits for the AC, if it even happens just 9 months from now, will be dropped, dramatically ;)/>

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Are they only training in light wind ? :wacko:/>

 

Lake Hauraki??

Why not?

 

Everyone knows the wind limits for the AC, if it even happens just 9 months from now, will be dropped, dramatically ;)

Postponed ? :);)

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Yep, that's the deranged storyline from Auckland. It goes along with the other brilliant idea that the May event in NYC, instead of a May second event in Italy, is part of the Big Plot by the Defender to hobble everyone.

 

It all fits, the fix is in, everyone is out to get them!

 

Sheesh, talk about not seeing the forest for the trees. Yep: squint-eyed is what all narrow-minded baloney is.

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Are they only training in light wind ? :wacko:/>

 

Lake Hauraki??

Why not?

 

 

I will not insult you with epithets.

 

However, you had better try and keep up.

 

Just 5 minutes ago, TNZ was being criticized for sailing in a lake!

 

The implication was "Go out in OR-type conditions and you too will join the pitchpole club".

 

That was until a taniwha arranged a tornado.

 

And now California lake-complainers have shut up.

 

With Christmas in the offing, it could be a good thing.

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I will not insult you with epithets.

GD made paranoid remarks about weather conditions being changed for the Match that just added to the other paranoid remarks recently, that do suggest very myopic, almost inbred, thinking.

 

But okay, I will raise the larger subject of truly independent Race Management, something GD can't bring himself to believe in and so would be unlikely to ever also implement, in a different thread.

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