Towards Smart Blades for Vertical Axis Wind Turbines: Different Airfoil Shapes and Tip Speed Ratios

Abstract

Abstract. Future wind turbines will benefit from state-of-the-art technologies that allow them to not only operate efficiently in any environmental condition, but also to maximize the power output and cut the cost of energy production. Smart technology, based on morphing blades, is one of the promising tools that could make this possible. The present study serves as a basis for identifying morphing airfoils as functions of azimuthal angle and tip speed ratio for vertical axis wind turbines. The focus of this work is on the combined analysis of three airfoil shape-defining parameters, namely the maximum thickness t/c and its chordwise position xt/c as well as the leading-edge radius index I. A total of 126 airfoils are generated. The analysis is based on 630 high-fidelity transient CFD simulations, validated with three experiments. The results show that with increasing λ, the optimal maximum thickness decreases from 24 %c to 10 %c, its chordwise position shifts from 35 %c to 22.5 %c, while the corresponding leading-edge radius index remains at 4.5. The results show an average improvement of nearly 0.06 in CP for all the values of λ.

Sistem for variable pitch vertical axis wind turbine

“…A thorough analysis of the aerodynamics of VAWT blades aiming to reduce instability is presented in [5]. Using the new Morphing Blades concept, the authors aim and succeed in demonstrating performance at the design model level that is simulated with various profiles and values for the TSR, gaining power, improving endurance and reliability.…”