Exploring the limits
Rolf Luchsinger, head of Empas «Center for Synergetic Structures», and his team wanted to make use of a demonstrator device to find out where, from an aeronautical point of view, the limits of the technology lie, and whether a Tensairity kite would offer any particular advantages. Brainstorming together, Luchsinger and a member of his group who had previously studied aerospace engineering came up with several ideas for suitable shapes and sizes. Based on these ideas a series of models were developed with steadily improved aerodynamic and static characteristics, shown by laboratory tests and computer simulations. The slimmer and more stable the air-filled wing spars, the more efficiently the kite climbs and therefore the better its pulling power can be harnessed to generate electricity.
The biggest Tensairity kite which Luchsingers team has developed so far has a span of 8 meters and a surface area of 11 square meters, and has undergone numerous load tests in the laboratory. With a weight of 2.5 kilograms it is designed to generate a tensile force of 1000 Newtons, and could in theory climb to an altitude of 4000 meters.