Analytical tether model for static kite flight

Nedeleg Bigi (1) , Alain Nême (1) , Kostia Roncin (1) , Jean-Baptiste Leroux (1) , Guilhem Bles (1) , Christian Jochum (1) , Yves Parlier

1 IRDL - Institut de Recherche Dupuy de Lôme

The use of traction kites as auxiliary propulsion systems for ships appears to be a high-potential alternative for fuel saving. To study such a system a tether model based on the catenary curve has been developed. This model allows calculating static flight positions of the kite on the edge of the wind window. The effect of the wind velocity gradient is taken into account for the evaluation of the aerodynamic forces acting on kite and tether. A closed-form expression is derived for the minimum wind velocity required for static flight of the kite. Results are presented for a kite with a surface area of 320 m2 and a mass of 300 kg attached to a tether with a diameter of 55 mm and a mass per unit length of 1:20 kgm−1. The minimum wind speed measured at 10 m altitude to launch the kite is found to be around 4:5 m/s. After the launching phase, we show that the optimal tether length for static flight is 128:4 m with a minimum wind speed of 4:06 m/s. The presented approach shows an error up to 9% for a zero-mass kite model with a straight massless tether regarding the maximal propulsion force estimation.

Keywords: Yo-Yo Airborne Wind Energy; Pumping Kite Wind Energy Rotating Reel; Magnus Effect; Skysail Energy; Kite Wind Generator; Offshore Airborne Wind Energy Converters; Bridled Kite; Tethered Kites; Energy Entrainment

Domains: Engineering Sciences [physics]; Mechanics [physics.med-ph]; Fluids mechanics [physics.class-ph]

Nedeleg Bigi, Alain Nême, Kostia Roncin, Jean-Baptiste Leroux, Guilhem Bles, et al.. Analytical tether model for static kite flight. Roland Schmehl. Airborne Wind Energy: Advances in Technology Development and Research, Springer, pp.57-78, 2018, Green Energy and Technology, 978-981-10-1946-3. ⟨10.1007/978-981-10-1947-0_3⟩. ⟨hal-01804758⟩