Zeeko Spitfire Hydrofoil

[BudhaNl]

Would that ease the learning curve for beginners as well?

Very interested too!

[borist]

No guaranties but certainly possible

[juandesooka]

Interesting to hear about new larger wings. Having the foil stable at slower speeds will be attractive ... Even if it comes at cost if some higher end speed.

Beginners .... I suspect it might. In my limited canard experience, one thing I have noticed ... not one wipe out yet due to ventilation (front wing surfacing). If the foil tends to sink down rather than crash, that could save a lot of wipeouts in those first few days.

[Big Wally]

Now that's an interesting point. I had heard mention of No front wing Ventilations.

[Pic]

Interesting to hear about new larger wings. Having the foil stable at slower speeds will be attractive ... Even if it comes at cost if some higher end speed.

Beginners .... I suspect it might. In my limited canard experience, one thing I have noticed ... not one wipe out yet due to ventilation (front wing surfacing). If the foil tends to sink down rather than crash, that could save a lot of wipeouts in those first few days.

Hi guys !
I know Nicolas, the Zeeko's designer and I had the chance to begin foil with the Spitfire and the larger wings.
First foil session in 20/25 knots with a 7m Notus Rev 2017, Spitfire with large wings, and Pocket Air board V straps on front foot and strapless back foot.

I was able to fly at my first session in both switch and normal position. I first rode it like a twin tip, but with a equal weight between my front and back leg. When I took more confidence with the foil, the chop made me fly over few meters. The more confidence I took, longer were my flight. At the end of the sesh (about 3/4 hours) I was able to fly for about 100 meters or more.

The larger wings of the Spitfire make the foil able to fly with low speed, which is very comforting when you're not easy with a foil and afraid about falling with it! With the large wings, you can fly very slowly, and if the wings go outside the water, you don't necessarily fall because you're flying at such a low speed with the lift on the back wing that the foil just dive down and you can keep going with the board on the surface.

I really enjoyed the session with the Spitfire and large wings and I'm convinced it's perfect for beginners !

If someone have questions about large wings go on! But keep in mind that I did only one sesh with it and it was my firt time foiling

[Starsky]

Hey Pic,

Nice to hear it was beginner friendly. Look forward to seeing and hearing a bit more about the new wings. With only the one producer, this concept is slow to gain momentum, despite coming from a reputable designer. Seems to be lots of development on the wave/cruise style of foiling with some pretty big wings showing up. Going to be interesting to watch the development over the next few seasons.

Be interesting to see if the concept shows up in Wind or SUP foiling.

[ronnie]

It is a concept that has characteristics that should give it a good niche in foiling.
Good at carving and good at jumping. Tends to sink rather than crash.

It's still a mystery as to how Nicolas is making it work.

With both wings lifting, it may be that as the angle of attack increases, the rear wing gradually provides a higher % of the total lift, so the centre of lift stays in approximately the same spot under the rider's centre of gravity.
That makes me think that the front wing might have to operate well beyond it's angle of maximum lift - ie. it might have a very delayed stall angle.
eg. the upper blue line in this graph - which shows how the lift gradually reduces with a different surface finish (compared to the other blue line, with a different surface finish - where the lift drops fast, with increased AOA).


It would seem to be an ideal project for some university with an interest in hydrodynamics, to test various wing profiles to find the most efficient combination for a pair of kitefoil, windfoil, or SUPfoil wings.

[BWD]

i'm curious about the surface of the spitfire stab, although nothing I have seen yet makes me think it is unusual -- how rough is it? the "right" roughness for speed/reynolds no/ etc I believe is known to delay stall by keeping flow attached better...

[borist]

It is machined G10. Relatively rough when compared to carbon foils. I was wondering the same thing, so I plan experimenting with making the surface smoother.

[BWD]

my understanding is that normally you want some roughness, typically in sailing or windsurfing 600 grit for hulls, with fins being smoother.
Kite foils seem to be in between, since they are bigger than a windsurf fin, smaller than a boat rudder.
The idea being that having some amount of roughness trips the fluid forming a thin layer of turbulent flow that will stay attached to the wing longer, versus a smoother surface that might have a tiny bit more "laminar flow" at the front but then transition to a bigger and draggier unattached layer with more turbulence and drag, and earlier, more abrupt stall, when that turbulence expands at higher angles.