New super high AR wings?

[Dave K]

Interesting topic for me since I’ve been debating the HA versus MA front wings for my own riding style. Finally got to spend a day switching between my standard go-to foil (Gong Veloce LT, 1350 sq cm/90cm and Veloce 39cm stab) and an ART 999 (borrowed from a friend) with 380 speed stab.

I typically ride flat water and chop conditions. An occasional downwinder in swell up to 3-4 ft, but that’s about it. I turn constantly (hate riding straight lines) and tack as much, if not more than I jibe. I’m 76 kg and ride a 4’9”/75 liter FSM strapless board

I know it’s not an ideal apples to apples comparison but it’s what I had to work with, and I’m not sure what you’d exactly consider apples to apples.

Summary. I really appreciated and enjoyed the 999. Of course it had tremendous glide, felt very stable with the 380 tail, and I was even impressed that I could get it to carve “respectably” (but not too hard!) during tacks to both sides. It would also flat turn (pivot turn) when required, for example at the latter stage of a tack or 360 when you want to tighten the turn radius quickly before stalling. But,….did it outperform my Veloce LT? In the glide category, of course it did. In the turning category, as you’d might expect, the Veloce at 90 cm span, clearly wins. Stall wise the edge also goes to the Veloce; not by a huge margin, but still clearly noticeable.

What surprised me the most was that for typical downwind pump and glide in chop, my Veloce actually does pretty well at keeping pace with the 999. I’m sure some would argue that getting the pump cadence of the 999 takes some time coming from a MA foil. No argument there, but still, I sure didn’t feel like it was going to be a night and day difference. As I see it, the Veloce’s are a very thin profile (low volume) which gives them a fighting chance against something like an ART. Anyway for my riding style I’m still ok sticking with my $320 USD Gong Veloce LT for now!

[fluidity]

My new foils are all high aspect. Building a 1.33 meter span foil at the moment. At the 3D printed model finishing stage currently. Axis have ART high aspect series. I'm making my current one specifically for pumping. High aspect not so bad to turn so long as you taper the chord. Being short chord they aren't as hard to turn as the big learner foils.

[fluidity]

Adding a bit more:
A chord tapered low aspect wing turns very easily. Double the span and halve the chord for each step of span it will also turn easily. But that shorter span low aspect ratio wing will be more draggy than the double span one. So then you shorten the chord of the high span wing even more, and you have a wing that only has issues turning, because it's going so much faster. And because it's more efficient, you can still go slow on it.

[Peter_Frank]

True, at these AR`s a correctly tapered wing will also have less induced drag yes.

Peter

[Dontsink]

Adding a bit more:
A chord tapered low aspect wing turns very easily. Double the span and halve the chord for each step of span it will also turn easily. But that shorter span low aspect ratio wing will be more draggy than the double span one. So then you shorten the chord of the high span wing even more, and you have a wing that only has issues turning, because it's going so much faster. And because it's more efficient, you can still go slow on it.

Cool!!
What taper ratio are you using?(TIPchord/ROOTchord).
From what i have read (about airfoils) tapering increases induced drag at high AOA(low speed) and decreases it at low AOA(high speed).Did you get results like that too?.

[fluidity]

Cool!!
What taper ratio are you using?(TIPchord/ROOTchord).
From what i have read (about airfoils) tapering increases induced drag at high AOA(low speed) and decreases it at low AOA(high speed).Did you get results like that too?.

At the moment it's buried in a partially infused sandwich of composites so I can't take measurements of it. But near the centre it's about 115, near the tips it's about 50. The centre itself, I have applied a function to thicken it to carry the Axis black fuselage front attachment foot. I expect to get some vorticies inbound of wingtips similar to what birds have but I'm not concerned about them. Target speed is not high, I just want low drag at around 8-20 km/hr speed which I'm fairly confident I'll get. The sweet spot for a lighter rider will be slower than for a heavier rider. Wave and manouverability are not major design influences for this wing, I just want to see how far I can push pumping efficiency and duration.

[Dontsink]

https://www.google.com/url?sa=t&source= ... mJfV7H62eX

This is a bit heavy reading for my knowledge,i have only taken a quick look
But they seem to find a sweet spot at 0.4 taper ratio whis is what you got.

[1234567Simon]

[consumer]

IMG_20220423_224320.jpg

Bro that thing is sick. Proto foil?