Design of Glider Airborne Wind Turbine.

Abstract

Producing clean and renewable energy is the aim of many countries worldwide. Wind is one of the most vast renewable energy sources. High-quality wind is available at high altitudes. To harvest such energy, wind turbines should reach such high altitudes. An airborne wind turbine system is conceptually designed to harvest wind energy at relatively high altitudes regardless of location. A glider is designed to carry a small wind turbine mounted at its nose. The glider is connected to the ground through a tether and electric wires to transmit power from the flying generator to the ground station. The resulting model airplane has a square wing with a Selig high-lift, low-Reynolds-number airfoil section (S1223-il) and a wingspan of 2 m. Tail airfoil sections are NASA airfoil 0012. The total mass of the glider is 3.35 kg. The aerodynamic design analysis is performed through CFD simulation. The forces and loads obtained from the CFD analysis are transferred to finite element software to perform structural analysis. Overshooting in lift and drag forces occurs in both cruise and nose-up flights. Such overshoot behavior is eliminated by the wind turbine rotation effect. The developed model meets the design objectives successfully, since both structural and CFD analyses show the aircraft's capability to carry the load. The CFD results prove that the glider is stable when the center of gravity is forward, and stability is achieved within 0.2 s. When the wind turbine is installed, there is slight oscillation in the lift force, but stability is reached within the design target of 0.2 s.