摘要
风力机叶片风振过程中,其气动阻尼表现出显著的时间和空间变化特性.然而,由于计算方法的局限性和工程效率的要求,实际工程中常忽略其三维时变性,采用经验值进行简化处理.本文基于改进的叶素动量理论(BEM)与几何精确梁理论(GEBT)的耦合方法,通过勒让德谱有限元构建了风力机叶片的非线性动力学模型,并基于变分原理线性化了叶片的非线性气弹动力学模型.在此基础上,将该模型与谐波平衡法(HBM)嵌套,完成线性系统在各谐波频率上的周期降阶,实现振动问题与流场问题的解耦求解,提出了一种高效求解风力机叶片三维时变气动阻尼的方法.通过气弹风洞实验数据的对比验证,分析了误差来源并验证了方法的准确性和可靠性.进一步地,以IEA15MW叶片为算例,在典型尖速比条件下系统研究了大型柔性叶片在旋转工况下气动阻尼的三维时变特性,并从叶片表面绕流特性出发揭示了其作用机理.算例表明,该方法不仅能够高效捕捉气动阻尼在时空上的演化规律,还能揭示其在展向负功与正功的动态分布、局部绕流涡结构的演化过程,以及吸力面与压力面气动载荷交替作用中的耦合效应.结果表明,所提出的BEM-GEBT-HBM三维时变气动阻尼计算框架在精度和效率上均具有显著优势,为超长柔性叶片的气动弹性设计与安全评估提供了新的有效工具.
During the vibration process of wind turbine blades,aerodynamic damping exhibits pronounced temporal and spatial variations.However,due to the limitations of conventional computational methods and the demand for engineering efficiency,its three-dimensional time-varying characteristics are often neglected in practice,and simplified empirical values are instead employed.In this study,a nonlinear dynamic model of the blade is developed by coupling an improved blade element momentum(BEM)method with the geometrically exact beam theory(GEBT)through Legendre spectral finite elements,and the nonlinear aeroelastic equations are subsequently linearized based on the variational principle.Building on this framework,the harmonic balance method(HBM)is embedded into the linearized model to achieve periodic reduced-order solutions of the system at each harmonic frequency.This enables the decoupled solution of the vibration and flow-field problems,and establishes a novel and efficient approach for computing the three-dimensional time-varying aerodynamic damping of wind turbine blades.The method is validated against aeroelastic wind tunnel experimental data,with the sources of numerical errors analyzed to confirm its accuracy and reliability.Furthermore,the IEA 15MW reference blade is investigated under typical tip-speed ratio conditions to systematically examine the three-dimensional time-varying characteristics of aerodynamic damping in rotating flexible blades,and the underlying mechanism is elucidated from the perspective of blade surface flow features.The results demonstrate that the proposed method not only efficiently captures the spatiotemporal evolution of aerodynamic damping,but also reveals its complex coupling effects in terms of the dynamic distribution of positive and negative aerodynamic work along the span,the evolution of local vortex structures,and the alternating aerodynamic loads on the pressure and suction sides.Overall,the BEM-GEBT-HBM framework provides significant advantages in both accuracy and computational efficiency,offering an effective tool for the aeroelastic design,optimization,and safety assessment of ultra-long flexible wind turbine blades.
作者
吴鸿鑫
柯世堂
王同光
任贺贺
田文鑫
Wu Hongxin;Ke Shitang;Wang Tongguang;Ren Hehe;Tian Wenxin(Key Laboratory of Jiangsu Province High Tech Design of Wind Turbine,Nanjing University of Aeronautics and Astronautics,Nanjing 210016,China;Department of Civil and Airport Engineering,Nanjing University of Aeronautics and Astronautics,Nanjing 211106,China)
出处
《力学学报》
北大核心
2025年第10期2319-2331,共13页
Chinese Journal of Theoretical and Applied Mechanics
基金
国家重点研发计划项目(2024YFF0505400)
国家自然科学基金重点项目(5231101289)
江苏省研究生科研与实践创新计划项目(KYCX22_0333)
南京航空航天大学博士学位论文创新与创优基金项目(BCXJ23-01)
南京航空航天大学研究生拔尖创新人才培养“引航计划”跨学科创新基金项目(KXKCXJJ202302)资助.
关键词
风力机叶片
气动阻尼
三维时变性
降阶算法
气弹模态
wind turbine blade
aerodynamic damping
three-dimensional time-varying characteristics
model order reduction
aeroelastic mode
