风力机大尺度变体叶片的刚柔耦合多体系统优化设计与集成方法的研究

To reduce structural load, enhance operation stability and energy capture efficiency of large wind turbine, taking the blade of wind turbine as research object, large-deformation morphing mechanism, serving as internal supporting structure, of the blade will be designed, and the external flexible skin structure will be studied and manufactured. Optimization on kinematics, dynamics modeling and relevant parameters of the morphing mechanism will be preliminarily studied according to morphing requirements and path planning methods. The selection method for flexible skin material with high strain and load bearing capacity and the 3D multi-objective topology optimization of supporting structure will be investigated. The coupled rigid-flexible multi-body system that integrates the morphing mechanism and the flexible skin will be carefully studied, to reveal the energy transfer mechanism of the coupled rigid-flexible system under load, and thus to establish the mathematic relationship between the parameters of material and structure and efficiency of the morphing system. A principle prototype will be manufactured, to validate the deformation performance of the morphing mechanism and the load bearing capacity of the blade configuration through numerical method, ground test and wind tunnel test. Then new methods for optimization design and integration of coupled rigid-flexible multi-body system for flexible morphing blade of wind turbine that satisfies the requirements of high load capacity, high stability and high energy capture efficiency will be eventually obtained. The new type morphing blade proposed in this project will solve bottle-neck problems on load bearing and efficiency of blade of large wind turbine, which is of great significance for the application of large-scale wind turbine, especially the offshore wind turbine in China.

为减轻大型风力机的结构载荷、提高其运行稳定性和能量获取效率，以风力机叶片为研究对象，拟设计叶片内部支撑大尺度变体机构，研制外部柔性蒙皮结构。根据变体需求和路径规划方法对变体机构进行运动学、动力学建模和相关参数的优化分析；探索大应变、高承载柔性蒙皮材料的优选方法及支撑结构的三维多目标拓扑优化；研究变体机构与柔性蒙皮一体化集成的刚柔耦合多体系统，揭示叶片在载荷作用下刚柔耦合系统的能量传递机制，建立材料、结构参数与系统变体效率之间的数学关系；研制大尺度柔性变体叶片原理样机，通过数值方法、地面试验和风洞试验验证叶片大尺度变体和承载的能力；最终获得风力机大尺度变体叶片刚柔耦合多体系统的优化设计与集成方法，从而满足大型风力机高承载、高稳定性和高能量获取率的要求。本项目提出的新型变体叶片可解决大型风力机叶片承载和效率的瓶颈问题，对推动我国大型风力机、尤其是海上风力机的应用具有重要的意义。

本课题主要针对风力机变体叶片关键技术中的柔性蒙皮和变体构型进行了研究。在柔性蒙皮研究方面，考虑蒙皮需要具有变形和承载双重能力，提出了适用于一维变形柔性蒙皮内部支撑的四种手风琴结构，通过力学理论对其结构特性进行了深入研究，并结合有限元仿真和实验对其面内外特性进行了验证；此外，将一维变形支撑结构向二维变形拓展，提出了适用于二维变形柔性蒙皮内部支撑的四种多胞结构，结合力学理论和有限元仿真对其面内外特性进行了研究。在变体构型方面，本研究设计并研究了一种变后掠叶片构型，其后掠角与面积可发生大幅度变化。本研究将基础力学理论应用于变体结构的设计与分析，为大型风力机的柔性蒙皮技术及构型设计研究提供科学的参考依据。在此基础上，本研究有望为大型风力机减轻载荷、提高稳定性和能量获取效率提供新的参考思路。