Evaluation of Aeroelastically Tailored Small Wind Turbine Blades (Final Report).

Griffin, D.

Technical Information Center Oak Ridge Tennessee

关键词: Wind turbine blades;    Aeroelasticity;    Design;    Rotors;    Energy reduction;   

RP-ID  :  DE2006861425

学科分类：工程和技术（综合）

美国|英语

来源: National Technical Reports Library

【 摘 要 】

Global Energy Concepts, LLC (GEC) has performed a conceptual design study to evaluate the potential for aeroelastically tailored rotors designed specifically for small wind turbines. This work has been performed for the U.S. Department of Energy under Grant No. DE-FG36- 03G013 133. Numerous studies have investigated the cost of energy (COE) reductions that can be achieved via aeroelastically tailored wind turbine blades designed to capture more energy while reducing or mitigating other system loads. The WindPACT Rotor Study predicted an 8.2% reduction in COE that was for a rotor that had the combined features of a slender planform with twistcoupling. The majority of recent work has focused on MW-scale turbines for which aerodynamic forces are dominant, gravity forces are significant, and centripetal loading is negligible. For small wind turbines (SWT) this is not the case. At the lower end of the SWT size range centripetal rotor loads are dominant, followed by aerodynamic loading, with gravity loads being negligible. This not only changes the turbine design challenge, but presents new opportunities for aeroelastically tailored blades. A report by Zuteck evaluated the potential for swept planforms to affect bend-twist coupling in blades, and showed that substantial coupling could be achieved with modest amounts of sweep. However, because that work was directed primarily toward MW-scale turbines, the work concluded that the feasibility of the concept was questionable due to the cost and complexities associated with curved blade spar structure. If the blade manufacturing method is changed to injection molding, as is common at the lower end of the small wind turbine size range, the cost penalty for complex shapes can be negligible and the cost-effectiveness of this approach dramatically improved. Because centripetal forces are substantial in small turbine rotors, the inclusion of pre-bending or pre-curving can be used to balance aerodynamic bending moments and offer additional design options for achieving optimal aeroelastic response. This concept forms the basis for the present study.