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Low AR foil kite

Posted: Sun Oct 01, 2017 8:05 pm
by kitexpert
Because it seems simple low AR foil kites have still have some use today I decided to make a quick design of that theme:

Image

There is some new (or not very often seen) twist anyway, the wingtip is non-bridled (like sonics) and kite has only A B and brake line rows. Bridle is cascaded in three levels to make it cleaner and less draggy. (Visible bridle lines to the wingtips are there only because of the limitations of the program.) Bridle is short.

Wingtip is angled.

Because every rib is bridled internal structures are not needed, except spanwise straps which are useful for any foil kite. Simplicity of the kite makes it easy to do and kite becomes light weight.

Re: Low AR foil kite

Posted: Mon Oct 02, 2017 11:25 am
by socommk23
Nice bit of work.
I went a different route. Modified my 8.5m pansh Adam to depower. Gave it to a friend to static fly as her first time with a foil kite. Turned away for 1 min to sort my kit. When I looked back she was up and foiling with it. For 3 hrs.

Re: Low AR foil kite

Posted: Mon Oct 02, 2017 12:16 pm
by kitexpert
Thanks, anyway it is just a quick study of the low AR kite. I'm not quite certain of using only A, B and Z, it may be better idea for high AR kites with short chords. I also might add canopy curve to make turning faster and less pivotal, but then of course PA would be smaller.

You can tweak this kind of details almost endlessly. I think basics of the design are ok, meaning cell count for the AR, plan view of the kite (2D shape), airfoil and bridle design.

One challenge to design this kind of kite is to keep the original concept. It is very easy to over engineer with CAD. This kite would have ca. 150 parts, so less than one third of the AR 6.3 kite I recently finished.

Last winter I fine tuned a Pansh Genesis for a local kiter. I could make it to turn faster by adjusting the bridle and I also made deflation valves a bit easier to keep open. The kite itself looked quite nice, good quality work and materials. When testing I noticed it was a pleasant and stable kite. However it felt too slow or soft kite for jumping (at least in normal winds), it has plenty of hang time though.

Re: Low AR foil kite

Posted: Mon Oct 02, 2017 12:25 pm
by socommk23
Pretty sure the genesis is the same wing as the adam. Your right they are a bit slow for jumping. I converted mine for low winds as it's relaunch is far better than an lei for foiling. So lo aspect foil kites deffo have a place.

Re: Low AR foil kite

Posted: Mon Oct 02, 2017 1:47 pm
by Kykeon
Is this screenshot from surfplan?
kitexpert wrote:
Mon Oct 02, 2017 12:16 pm
I'm not quite certain of using only A, B and Z, it may be better idea for high AR kites with short chords.
That was exactly what I thought when I saw the drawing

Re: Low AR foil kite

Posted: Mon Oct 02, 2017 2:50 pm
by kitexpert
Low AR foil kites are very easy to use kites, they don't do any radical moves etc. Very usable for high winds also, like much praised small sizes of Access. And when wind is 30-40kn there is enough performance even for low AR for sure.

Picture is a screenshot from Surfplan. It is a good design program - not perfect but good enough.

FS Viron has only A and Z, and one single line at wingtips which is pulled 1:2 (like B row). I've sometimes tested the stability of kite by flying on A only, it is possible. There is however some kind of risk kite does not keep its shape when powered if there is not enough bridle support. Also camber change during the sheeting becomes less controlled/possible with fewer bridle line rows.

Re: Low AR foil kite

Posted: Sat Oct 07, 2017 8:37 pm
by kitexpert
Another version of the low AR theme. Much more canopy curve, slightly thicker airfoil, different air intake locations and different bridle. I like this one more.

Image

Re: Low AR foil kite

Posted: Sat Oct 07, 2017 9:54 pm
by Hansen Design
Cheers!
SnowKite Foil.JPG

Re: Low AR foil kite

Posted: Sun Oct 08, 2017 7:39 am
by stefFZ
HI Bill!

I remember that you talked about a depowerable foil when we did the interview on FZ:

Interview express Bill Hansen, Switchkites designer

Are you about to release one at Switchkites? That would be very interesting.

Stef

Re: Low AR foil kite

Posted: Sun Oct 08, 2017 11:35 am
by kitexpert
Good to see you here, Mr Hansen! I guess there is nothing new under the sun... Good kites look similar? 8)

However there is room to design details differently and trying to achieve desired flying characteristics. Kiting has diverged to many disciplines giving more chances to specific kites than ever.

Usually I prefer kites with powered turns, because it makes active flying more sensible and fun. But when I practiced backroll kiteloops I was pleased kite I was using had a pivotal turn :)

I've not seen this kind of low AR foil kites very interesting projects because they are so much simpler and have inferior performance to high AR kites. But trying to do it better than before gives a challenge anyway, and simplicity makes kite much more easier to finish which is of course nice.

I'll start kite something like in this thread probably quite soon, after I've finished design process. Low AR and low cell count (now 17) will be there, but many details I've not decided yet. I need some kind of reason for every one of them, nothing comes by itself.

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Thank you Stef for your work for foil kites and also for that interesting interview. I didn't know you are the admin of LesFoilz (also because of my french is rubbish), I appreciate it a lot :thumb: