pacice

Foiling Monohull - what would it look like?

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12 hours ago, Rasputin22 said:

That would be heeling/canting the wrong way Rob. That foil surfer is setting up for a gybe carving turn and would be heeled the other way when you consider cant. 

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Image result for foil windsurfing

Old school foils

Image result for foil windsurfing

So the top picture here, (couldn't seem to find the heart to [snip] her,

shows a windsurfer with moderate windward cant, much less than 45 i reckon.

Do you have any pictures of extreme windward cant on a windsurf board where the wing is starting to break surface as you mentioned?

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It really doesn't get any clearer than this - your question and my response. Are you dyslexic?

22 hours ago, barfy said:

how will a windsurfer get extreme cant on the foil?

 

12 hours ago, surfsailor said:

Via the same mechanism as the kites - heeling the board to windward. 

 

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are you fucking dumb as a sack of fucking hammers, show me a windsurfer with "extreme cant" like you were talking about. fucking windsurfers

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1 minute ago, barfy said:

So the top picture here, (couldn't seem to find the heart to [snip] her,

shows a windsurfer with moderate windward cant, much less than 45 i reckon.

Do you have any pictures of extreme windward cant on a windsurf board where the wing is starting to break surface as you mentioned?

Equipment is being developed for the new foiling discipline on the pro windsurfing tour right now. I doubt anyone is going to share pics of what they are working on. Including me.

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3 minutes ago, barfy said:

are you fucking dumb as a sack of fucking hammers, show me a windsurfer with "extreme cant" like you were talking about. fucking windsurfers

Sure - that's about 30 degrees, and the rail of the board is nowhere near the water surface:

Image result for foil windsurfing

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oh.

you should be in the AC50 circus of un-substantiated pipe dream forum then.

You always debate based on your supreme knowledge of everything that is too informed to share any solid facts.

par for your course.

your head is so big it's got it's own weather system

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2 minutes ago, surfsailor said:

Sure - That's about 30 degrees, and the rail of the board is nowhere near the water surface.:

Image result for foil windsurfing

and his ass is just about dragging due to the lever arm from the wishbone

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Just now, barfy said:

and his ass is just about dragging due to the lever arm from the wishbone

His ass is no closer to the water than the rail of the board. He's in such a steady state that he's able to remove one hand from the boom and drag it in the water.  Holy crap, dude.

LOL

 

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Foil racing in Sylt, October 2017. That windward heel (cant) is not an illusion - this guy won one of two races held, and wound up third for the event, competing against more experienced foilers who were riding flatter. As the kites have shown, the future  - especially upwind - is windward heel/cant.

SY17_sl_Jordy_flying_high.jpg

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where on the time line are things at regarding when any of these circus freak shows will be revealed to the unwashed masses? someone told me a theoretical rendering of one reminded him of a urinating dog, though from a design perspective, they will be marvels of modern machinery.

so when will a design be revealed?

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10 hours ago, surfsailor said:

 As the kites have shown, the future  - especially upwind - is windward heel/cant.

SY17_sl_Jordy_flying_high.jpg

are you simple, or am I missing something? of course foiling kites, moths, foiling sail boards, etc sail with weather cant.

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On 4/21/2018 at 9:56 PM, barfy said:

how will a windsurfer get extreme cant on the foil?

 

On 4/22/2018 at 8:12 AM, surfsailor said:

Via the same mechanism as the kites - heeling the board to windward. 

 

12 hours ago, barfy said:

yea,

you seem to have the wind direction a little bit confused surf sailor...that's draggin him downwind.

no matter

 

12 hours ago, surfsailor said:

No, you are confused - heeling to windward (as the kites are also doing in the pic you posted) increases lateral resistance, potentially past the null point (leeway angle less than zero). Heeling to leeward would drag the guy downwind.

The kites are achieving nearly 60 degrees of cant (windward heel) with the 110 cm foil masts.

 

12 hours ago, barfy said:

The picture that ROBG posted and you commented on has been pointed out to be canted downwind.

I have seen many times top racers in NZ with way over 45 degrees of windward cant, just couldn't find a picture.

Of course you know that I use pictures to debate with rather than asserting my opinion.

 

 

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4 hours ago, 3to1 said:

where on the time line are things at regarding when any of these circus freak shows will be revealed to the unwashed masses? someone told me a theoretical rendering of one reminded him of a urinating dog, though from a design perspective, they will be marvels of modern machinery.

so when will a design be revealed?

When the first boat is launched, so you have about 12 months to wait.

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5 hours ago, 3to1 said:

… or am I missing something? of course foiling kites, moths, foiling sail boards, etc sail with weather cant.

Sailboards have the rig heeled to windward, but from what I've seen, foiling boards seem to sail fairly flat, they aren't heeling the foil. It's nothing to do with needing the board to be flat to generate lift: if more lift is required, they can increase the AoA through weight redistribution (and likely sail trim).

I think sailing with the foil heeled takes more skill though, as the strut also starts to provide vertical lift so steering inputs change the lift, so more variables in the mix. It's an old trick on Moths when falling in to windward and you're already fully sheeted on, bearing away sharply helps to lift you back up.

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16 hours ago, sclarke said:

When the first boat is launched, so you have about 12 months to wait.

Ahhhh....and the non-surrogate that someone assured us was already in use - what about that as a 'design reveal'?

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On 4/22/2018 at 2:50 PM, hughw said:

Doesn't really affect the situation as to whether the foil in question is providing sideforce and/or direct lift.  Increased speed results in lower Cl for the required sideforce.  V^2 and all that.   Flaps are fine for relatively small changes in Cl and thus ride height, but will be slower reaction than that derived from rudder elevator effects.   Combinations of  both will be in order to deal with the various situations I reckon.   ...

I don't follow why you think flaps are slower than rudder elevator - I would think it's the other way around.  The Design Rule allows flaps up to 50% chord.  Each degree of deflection of a 50% chord flap produces a change in lift that is 80% of what you'd get with a one degree change in angle of attack of the entire surface, so flaps can produce a large amount of lift.  Flaps can be moved much faster than raking the rudder, and the elevator needs to change the pitch angle of the entire boat to change the lift on the main foil.  

For controlling ride height, I would use foil flap as the primary height control, and command elevator angle with flap command passed through a limited integrator.  This would use the flap for quick response and the elevator for long-term pitch trim.  The integral control of the elevator would drive the steady state flap deflection to zero, resulting in the foil being driven to the angle of attack needed for trimming at the desired flying height, while preserving the entire flap authority for short-term control.

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Hi,

These last few days, I have been traveleing to the sea, and noticed similar features on Hydrofoils from very different machines

1-A big all white Oman trimaran in Lorient harbour

2-A foiling windsurf

3-An A-Cat Exploder 

All of them seem to share common features:

1-A sharp leading edge 

2-A maximum thickness which seems a little aft

3-A Concave shape on both sides of the last 35% of the wing section leading to very low exit angle.

Main Difference: The bigger the boat the larger the camber and thickness (for structural reasons I guess).

We still have to wait to see what kind of foils the new AC boat will carry, in the meantime  that a few infos to chew for the addicts.

Cheers 

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1 hour ago, Terry Hollis said:

No information on it but it seems that the AC75 spin off has already begun ..

 

Sure that's not the "ugliest boat" competition?

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I doubt that is a 'photo' but a rather clever composite render with some well done photo background/foregrounds. The transparency of the jib and main don't look quiet right. 

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1 hour ago, Tornado-Cat said:

Difficult to know how this artwork reflects reality but the boat does not look fast, mainly with the big gennaker.

Agreed - it's not moving at all in the picture... :rolleyes:

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10 hours ago, Terry Hollis said:

No information on it but it seems that the AC75 spin off has already begun ..

35564342_1044733452369856_67768581585234

Time to come clean, Terry.  Image origin please?

This looks very "wooden" and multiple critics here have picked up on good points.

Web search for FlYacht comes up empty.

At least though, someone deserves credits for some pretty nice PhotoShop skills.

 

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31 minutes ago, KiwiJoker said:

Time to come clean, Terry.  Image origin please?

This looks very "wooden" and multiple critics here have picked up on good points.

Web search for FlYacht comes up empty.

At least though, someone deserves credits for some pretty nice PhotoShop skills.

 

I found the image on Facebook and extracted the url and the photo was all that would show.  The beginning of the url does not do anything https://scontent.fakl2-1.fna.fbcdn.net but it does seem to be a fake site .. :)

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