Sustained flight of an unmanned glider by winching.

Abstract

Abstract. One of the newest technologies to produce environmentally friendly energy is to harness wind energy by sending up unmanned gliders that are con- nected to a generator on the ground through a cable. One of the biggest chal- lenges with this technology is to keep the glider airborne when the wind is still. This thesis work investigated methods to do this by reverse pumping of the cable. Two methods to lift the glider are tried and then compared with each other to see which one is the most energy ecient and the most practical. In method 1 the glider dives with an applied force from the cable and take use of the gained speed to ascend. In method 2 the glider is winched with a constant lead angle. In the descent phase was the trajectory for maximum endurance calculated. A comparable value was found, the energy consumed per gained meter. This showed that method 2 consumed about one sixth of the energy that method 1 did. The whole ight, the ascend and descend phase combined, found out too keep the glider airborne for a sucient time and at a low enough energy cost. This thesis has only looked at the basic mechanics of ight to determine if it was possible to keep the glider airborne by reverse pumping of the cable. To analyze this method more thorough some further analysis is required. This analysis could contain simulation in 3D, use of real regulation, consideration of weather conditions and also to see the cable as nonlinear