Affiliation:
1. Wetzel Engineering, Inc., P.O. Box 4153, Lawrence, Kansas 66046-1153
Abstract
This paper reports an investigation of the use of off-axis carbon fibers in the all-carbon spar cap of a 37-m wind turbine rotor blade to induce twist-flap coupling. Many studies have been published on the structure of wind turbine rotor blades incorporating off-axis fibers; none has studied optimizing the blade structure simultaneously considering the angle of off-axis material, the fraction of off-axis material, constraints on cross-fiber and in-plane shear strength, constraints on tip deflection, and blade cost. A parametric study has been conducted varying the angle of off-axis fibers from 5° to 25° and varying the volume fraction of off-axis fibers in the spar cap from 10% to 90%. In all configurations, the remainder of the spar cap material is 0° carbon fiber. The spar cap thickness has been adjusted in each blade to simultaneously minimize the weight of carbon material, and hence the blade cost, while satisfying constraints on carbon fiber strain and tip deflection. The study also examines the cross-fiber strain and stress and the in-plane shear stress in the 0° and off-axis carbon layers. The conclusion of this study is that the optimal angle for most cost-effectively achieving twist-flap coupling—considering constraints on fiber strain, cross-fiber strength, in-plane shear strength, and tip deflection—is closer to 7.5° than the 20° that has frequently been reported by prior researchers. As much as 90% of the spar cap carbon fibers can be rotated to 7.5° off-axis before in-plane shear strength is exceeded.
Subject
Energy Engineering and Power Technology,Renewable Energy, Sustainability and the Environment
Reference16 articles.
1. Lobitz, D. W., Veers, P. S., Eisler, G. R., Laino, D. J., Migliore, P. G., and Bir, G., 2001, “The Use of Twist-Coupled Blades to Enhance the Performance of Horizontal Axis Wind Turbines,” SAND2001-1003, Sandia National Laboratories, Albuquerque, NM.
2. Active and Passive Aeroelastic Power Control Using Asymmetric Fiber Reinforced Laminates for Wind Turbine Blades;Karaolis
3. Kooijman, H.-J. T.
, 1996, “Bending-Torsion Coupling of a Wind Turbine Rotor Blade,” ECN-I-96-060, Netherlands Energy Research Foundation ECN, Petten, The Netherlands.
4. Ong, C. H., and Tsai, S. W., 1999, “Design, Manufacture and Testing of a Bend-Twist D-Spar,” SAND99-1324, Sandia National Laboratories, Albuquerque, NM.
5. Concepts for Adaptive Wind Turbine Blades;Ashwill
Cited by
21 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献