强风作用下风力机叶片气弹响应的实测和数值模拟研究

Wind velocity and wind direction would change suddenly during strong wind, which caused the wind turbine blade damage, including fracture and tears off, and the collapse of the whole wind turbine in severe cases. In recent studies, the aeroelastic response analysis of wind turbine blades is mostly based on the turbulence model of wind velocity, while the field measured data is scare. In addition, the aerodynamic calculation of blade mostly adopts the standard suggested formula, without considering the time-varying characteristics of wind load. Therefore, it is necessary to conduct field measurement, numerical simulation and finite element analysis on the blade aeroelastic response under strong wind. .In this research, the horizontal axis wind turbine blade is taken as the research object to conduct the following work. Wind field measurement is carried out at hub height of the wind turbine under strong wind. Then the wind field of the wind turbine blade is simulate and verified by the field measured data, after which the wind load simulation on blade is conducted. Meanwhile, the 3D finite element analysis model of the blade is established considering the anisotropy of materials, and the simulated wind load is applied to the finite element model to calculate the aeroelastic response of the blade, by which the stress distribution characteristics of the blade is obtained. Moreover, the weaken stress position of the blade is determined for reinforcement, and the reliability of the blade reinforcement measure is verified using two steps combined with the aeroelastic response calculation of the whole wind turbine model..The research is for the purpose to carry out the above research to reveal the aerodynamic load characteristics of wind turbine blades, to obtain more realistic blade aeroelastic response, and provide a feasible plan for the safety and reinforcement design of wind turbine blades under strong winds.

强风作用下风速、风向的突变常造成叶片的折断和撕裂，严重时造成整个风力机组的倒塌。现有研究中，风力机叶片气弹响应分析多基于风速的湍流度模型，缺乏实测数据，且气动力计算多采用规范建议公式，未考虑风荷载的时变特性。因此，有必要对强风作用下叶片气弹响应进行实测、数值模拟和有限元分析。.本项目以水平轴风力机叶片为研究对象，主要开展：①强风作用下，风力机轮毂高度处的风场实测研究。②基于实测风场数据，模拟得到与实测风场较为一致的风力机叶片风场，进而开展叶片的风荷载模拟。③建立考虑材料各向异性的叶片3D有限元分析模型，将模拟风荷载施加在有限元模型上计算叶片的气弹响应，得到叶片的应力分布特征。④确定叶片的应力薄弱位置进行加固，并结合整机模型分两步验证加固方案可靠性。.本项目旨在开展上述研究，揭示风力机叶片的气动载荷特征，获得更接近实际情况的叶片气弹响应，为强风作用下风力机叶片的安全性及加固设计提供可行性方案

在“双碳”时代背景下风力发电作为一种清洁、高效的能源利用方式，受到前所未有的重视。为研究风电场风场特性、风力机叶片表面风压分布特征及风荷载作用下的叶片气弹响应等内容，开展了无人机搭载风速仪测风方法准确性的风洞试验，浙江台州某沿海风电场风特性的现场实测，风力机叶片流固耦合的数值模拟及有限元计算等工作。所完成的工作取得了如下成果：①提出了风速仪距离无人机顶板20cm为无人机测风的最佳安装高度，给出了无人机测风的平均风速修正公式；②构建了沿海风力机尾流风场实测系统，首次使用无人机进行风力机尾流实测；③深入研究了风力机尾流效应的变化规律，揭示了垂直方向尾流风速的非对称性分布特征，0.5倍风轮直径处尾流风速的双峰分布特征，水平方向尾流风速向下游扩张的发展趋势，近尾流区湍流强度是来流区的1.3~1.5倍；量化了不同来流风速下的尾流风速亏损；揭示了上风向建筑群对风力机前方来流风速的影响规律；④提出了适用于A类风场风力机下游尾流风速剖面的预测公式；⑤率先采用基于多孔介质的二维代理模型进行风力机尾流的数值模拟，并将此代理模型运用于风电场的布局优化中，得出风电场与正北方向的夹角等于 0°时年发电量最小；⑥系统的进行了全尺寸风力机叶片风场和风压数值模拟，通过对比近尾流风速分布的数值模拟结果与实测结果验证了数值计算的准确性；获得了风力机叶片风压沿着叶片展向的分布特征；⑦建立了风力机叶片的流固耦合系统，系统计算了额定风速下叶片的变形和应力等气弹响应，叶片挥舞变形最大值出现在0°方位角下的叶尖处，为1916mm，与静力加载试验中最大挥舞工况的叶尖变形2299mm相差约16%；叶片应力最大值出现在叶片迎风面0.78倍风轮半径处，位于前缘侧与大梁的交界处，该区域为叶片应力集中区域，属于薄弱位置；⑧提出了一种风力发电设备叶片智能调节机构，提高了叶片的变桨调节能力。综上，本项目研究成果可为沿海风电场的风资源评估，在役风力机叶片运维中的疲劳和损伤分析提供指导。