Privatbesitz Genf/Swiss
The four concentric rings degressively sized have two contrariously airfoil designed cross sections each, one semicircle producing ascending the other descending force respectively the rings being rotated by the wind thus. The two bearings of each ring are bedded in the next greater ring, each time distorted by 30 degrees. I've designed this object together mit Ralf Gschwend from Genf and successfully built an operative model of 1,20 m size.