High Pressure kite by Bruno Legaignoux

[Toby]

I mean small or big company

Sure, looking at 18...always, since I don’t do trainer kites anymore

[joriws]

When I checked Bruno's site and table "Why the new kite will rev the market" I directly had some doubts..

relaunch on light wind?

- Relaunch if airfoil gets parallel to surface - to be able to relaunch you must have enough wind which can blow under the airfoil. So with HPK if you loose tension of 2 lines it is immediately game over on relaunch. If HPK is stationed like in picture all lines tensioned then it probably has good reverse flying characteristics but it is only part of relaunch problem. Can HPK be put on water surface, let it drift and when lines tension launched (drift launch)?
- How you get air underneath the HPK? Be realistic about it and address the problem because I don't see anything on the constuction allowing wind to blow between water and kite. Classic tubes gets air in underneath struts which (struts) should never be laying on water. Even KBM Cloud air can get via twisted LE and hopefully fill the canopy underneath.
- HPK seems to be so thin on hose profile that water if there are small waves will get on top of the airfoil and Game over! Try launching stunt kite which is parallel on the ground even without water! Now imagine water surface tension sucking the kite in with water on top.

packed size and weight

- you did not count compressor or 7 bar tank to inflate it? You travel abroad and want to kite? Rent a scuba tank with 7 bar regulator?

--

A couple of things on table is L/D question. Sure you can have a kite that is like a wasp (like 4-line stunt kite Revo). But there is not much lift involved. If you look Tilmann's video, there is a lot of movement on the sky but it does not transfer to movement of the buggy. If that kind of physics were true IRL we all would already kite with 1m2 kite (napkin) because it can be moved around with speed and there was no need for kites to evolve how they are right now.

Sure HPK could bring something new and if it is very low drag there is potential kite land speed record breaker.. But for jumping you need certain drag balance for lift that kite do not overfly easily. It needs high lift and it cannot shoot past you to outside of wind window because then you drop like a stone.

[tilmann]

@ joriws: my kite was just too small in the video as the size is only 3m in 5 Bf. and the sand was´nt really hard.

In general we just have to make the kites bigger. We saw the same development in windsurfing in the 80s and 90s: the sails became flatter, easier to handle, faster ... and bigger.

The new sails suddenly had this light and easy feeling and you was not afraid of gusts anymore. Old windsurfers still know the difference
Imagine you are standing on your board and you don´t have to depower anymore, when a gust is coming.

[longwhitecloud]

if this enables more affordable kiteboarding for all, and the end of flying sleeping bags then awesome.

turns like a cquad

what is the situation in france with kiteboarding and sailing... was there a court case?

[kitexpert]

Perhaps it would be more appropriate to call this kind of kites "thin inflatable kite" or something, because high pressure is not the target neither it is an advantage. I also have some doubts if very thin LE is a good thing because it makes LE "sharper" which very probably makes kite less stable and twitchier in behavior. But of course it makes kite also lighter in weight.

For small struts I don't see much drawbacks for thinness, as far as there is enough rigidity. One might be added effort to fill them or added complexity if some kind of one pump system is there. In general it should be advantageous to have different diameters and pressures for LE and struts, because they are of different sizes and functions.

I'm not sure why traditional LEI design should be abandoned because of thin structure.

[PullStrings]

A design with wider tips would absorb the gusts better......just kidding....just saw some similarity in the shapes...not trying to offend...keep up the good work !

[brunolgx]

I don't intend to address myself all the issues that can have the HPK. The brands and their designers should design kites corresponding to their knowledge (inflatable or ram air or single skin) and try to address the corresponding issues, playing with the hose diameters, hose material and weaving, bridles...
High pressure is a technology which allows to make cheaper kites. I chose one design among many possible ones which can benefit from this tecnology. I can't explore all the possibilities alone.

[kitexpert]

Goal to make kites lighter and less expensive is of course appreciable. I had couple of years ago same thought to use some kind of hoses as struts but I couldn't see how it should be done in practice and where to get such hoses etc. But I found out a method how to make struts for much higher pressure than it is in normal LEI's.

HPK kite presented in this topic is first of it kind and there is many practical problems solved. Achievement well worth

[grigorib]

Bruno, you're inventing right things. I hope your designs get picked faster. I hope one/many of big guys pay your ticket and your time to bring your invention to a nice kiting paradise spot for a demo so we don't have to wait for 5 years for it to become a reality.

[tilmann]

I think many of us would be happy already, if the diameters were 2/3 of the diameters today.