Lets try this one!
Try to imagine this if you can:
A perfect 30 Knots cross onshore from the West at Avalon (thats in WA guys, and west is GOOOOOD) and there's an Atom SLE 9m and a PL Venom 10m having fun in a reasonable metre and a half to two metre swell. They are sharing it with a couple of pole vaulters who appear to be making the best of it too. But wait...theres someone in the carpark...someone not happy coz he cant get out...its too strong....the 7m waroo is too large, unpredictable, wont auto zenith or something..but hang on...its ..no it cant be.. it is.. no surely not... yes it is its 'SLAVE. Bugger me if he he isnt overheard to ask the venom flier at the end of the sesh "wot size doona ya got?" he's told its 10m and then comes out with "and wot size do you fly when its light?"
Waveslave to
Carpark Attendant in 2 minutes!!!!
But seriously, lets answer the original question:
The PL kites arent strange in the fact that they auto zenith. Take any glider or airoplane model ( the flying ones..not airfix models you fool!) and tie a line to their Centre of Gravity and then run and itl fly (and auto zenith). As the plane rolls to ,say, the left then the right wing loses lift due to the dihedral effect (the upward tip of the wings, this means as the plane tips left, the right wing becomes effectively shorter than the left wing causing the left wing to generate more lift - self stabilising.) The PL kites have a dihedral effect in the way the kite deforms as it moves from left to right, losing lift from the side thats rising by deforming the trailing edge.
The real question is why dont the inflatos do it? and also why dont flysurfers cos they are foils eh???
The reason for inflatos lies in their use of a single skin attached to the top of the inflated
price I mean the inflated tube. This generates a large amount of turbulance behind the tube and beneath the skin at is leading edge. This turbulance causes lift and therefore the kites work well as traction kites, however they are unstable as the turbulance causes the kite to 'fall' off the zenith, and as it falls the turbulance increases in the section of the kite most horizontal, the kite cant deform (due to the rigidity of the inflato) to allow the excess lift to be lost, so this causes even more lift and therefor falls faster, its a runaway effect.
Flysurfers are German! Plus all the lines prevent the kite from deforming, its like trying to get an F14 to glide.
As long as the flier keeps controlling the kite then no problem.
Now then.. auto zenithing inflatos..mm
Ah ha, so now we know the truth, the auto zenithing kite flown by the
Carpark Attendant must have been an unbridled foil (so wot was he doing with the pump while he thought it was an inflato
)
