Postby Regis-de-giens » Mon Apr 25, 2016 9:53 am
When I have transformed my ex Speed 2 19m to a single skin, wings were collapsing a lot ; internal pressure of standard double skin adds huge rigidity that allows to twist the wings more inward hence increase agility and performance ; single skins like peak need therefore to have really flatter wings with higher Angle of Attack on the wings to keep their shape, which kills the L/D ratio and the up-wind ability.
This hydrid concept could solve part of this single skin problem and reduce maybe the AoA of at the wings thanks to the added rigidity of the lateral closed cell. The designer told me that (according to him) L/D ratio ( performance) was comparable to a Flysurfer Speed. Well...to be confirmed but certainly better than single skin Peak...
Regarding relaunch, I noted that with my 9m peak on snow, there was a significant problem in hyper light wind : if a zero-wind lull comes, when it backstalls up to the ground , the absence of structural rigidity makes the kite completely touch the ground, up to the Leading Edge, with a very limited chance that it will catch properly the next flurry of wind, specially if you are in a little bowl. A closed cell or even open cell kite will keep a minimum of pressure putting the LE higher and better chance to catch the next wind increase. The 3 cells of the Ninox could maybe save this type of relaunch.
Relaunching in the water: still risky (knowing that the LE is not closed on the Ninox), but its low weight will reduce the chance to touch the water. And in case of irregular wind, it would allow both to keep the kite in the air in lulls, but also accept the risk to put it down the (flat ... ) water when wind is above 6 knots .