Power Kite Forum

ARC Kite with internal tube hybrid

herc - 9-11-2009 at 09:50 AM

what do you think about this idea:

place a tube with a small diameter along the leading edge of an arc kite. tie the tube relatively loosely to the first inner strap of the arc (the one closest to the LE). pump the tube from the side.
i hope this would give:

1. beter launch if not fully inflated - the kite would not bowtie that fast
2. prevent inverts more often
3. much better water relaunch, as the kite will not have sticky tip-over-tip situations

the tube could be a very light one, because it does not need to support tension - this is handled viea the strap. its just there to keep the kite open in lulls, during launch and on waterrelaunch.

what do you think?

power - 9-11-2009 at 09:53 AM

Interseting idea, but I think it would change the aerodynamics of the kite too much to still allow it to fly well.

herc - 9-11-2009 at 10:02 AM

remember, i was thinking about an internal tube with a quite small diameter. how could that change the profile of the kite? added mass would be a problem, but i think the tube could be very light. it just should keep the kite more open in the common difficult situations of arcs.
pumping the tube should even be optional!
besides that: a small leading edge bridle could also help alot. you know - rein art kites already experimented with that idea:
http://www.rein-arc.be/

BeamerBob - 9-11-2009 at 10:04 AM

It would completely change the launch/relaunch scenario and we would have to pump AND preinflate.

herc - 9-11-2009 at 10:08 AM

just edited my previous post: pumping should definitely be OPTIONAL. just pump if in difficult situations: low wind, extreme gusts. and because of the thin diameter, you would have to pump considerably less , with less pressure.

at least, the hybrid could have superior aerodynamics compared to classic tube kites: better profile, lighter tube, better mass distribution (no heavy head)

snobdr - 9-11-2009 at 10:14 AM

If you add a tube you also have to add the sleve to hold the bladder. Now you putting extra weight on a kite that is know for not having any low end, further reducing its low wind ability. You will be adding stiffness to the kite wich will reduce its ability to handle gusts. Add to that a bridal and any gust munching is lost.
Dont try to reinvent the wheel, just buy a LEI.

BeamerBob - 9-11-2009 at 10:31 AM

Quote:
Originally posted by snobdr
If you add a tube you also have to add the sleve to hold the bladder. Now you putting extra weight on a kite that is know for not having any low end, further reducing its low wind ability. You will be adding stiffness to the kite wich will reduce its ability to handle gusts. Add to that a bridal and any gust munching is lost.
Dont try to reinvent the wheel, just buy a LEI.


Or enjoy all the benefits of arcs as they currently exist. Horses for courses as they say.

herc - 9-11-2009 at 10:32 AM

well said. true words.
thinking of it again, the whole kite should be the tube! but thats what they already tried with the charger: keeping more internal pressure, making it stiffer.
who knows, maybe the next iterations of arc kites will further increase internal pressure with better air - vents and better air-sealing zippers and stuff.

and they should make the damn arcs lighter! the concept is so great. why is it so bad at low winds.. thats a pitty. we should file a request to PL/vliegerop for some sort of "deluxe" cloth with much less kg/sqm. if flysurfer can do it, they should be able to do it as well.


besides that:

i dont see a change in the launch process. the small tube should be flat, of course, no curvature. that way the launch would be identical to current arcs. the small, ultralight tube should just be so strong as to hinder bowties.

another thing: who knows? maybe with better air vents, you just would have to pump tha small internal tube, without any bloody prefilling!!! the bowtie wont happen, and the arc could inflate during launch.

by the way - i was told that the old bombas and guerillas did not need any/much prefill. for whatever reason?!?!

PHREERIDER - 9-11-2009 at 11:04 AM

maybe on a super long trek 60 miles to another island but the launch would be a different animal.

really kills the concept ...and what shape would you give it ...and average of many? i believe it my hamper flight behavior.

i am sure it would work in some back up fashion but the real problems. WHEN this thing fails it may fly so much better minus the weight it would never be replaced or maintained. dragging a pump forget it

dylanj423 - 9-11-2009 at 12:22 PM

the low end is not from the cloth, it is from its arc-ness... it is inefficient, which is why it needs more wind per square meter.... flysurfers are completely different, their bridle makes them far more efficient sails

the inefficiency is what creates the smoth delivery of power, too, so inefficient has its advantages sometimes...

ripsessionkites - 9-11-2009 at 02:12 PM

look up jojo wet, they used a inflatable cross section inside