文档介绍：汕头大学硕士学位论文摘要 I 摘要由于自然界的风在时间和空间上的多变性,现代大型水平轴风力机的柔性部件—叶片和塔架经常承受较大振动和变形, 这不仅会引起结构的附加应力,影响其结构强度,还会对叶片自身的气动性能产生影响。气动与结构相互作用,还会形成复杂的流固耦合过程。因此精确预测风力机结构在时变载荷作用下的动力响应,具有重要的工程实际意义。本文首先对风力机叶片的空气动力特性进行了分析,阐述了叶素—动量理论及其各种修正方法,同时分析了动态失速和动态入流,以更精确地计算风轮的动态气动特性。对风力机结构所受外部时变载荷进行了分析,为风力机结构动力响应分析提供了计算基础。为了获得水平轴风力机叶片和塔架在时变载荷作用下的动力响应,把叶片和塔架均简化成变截面悬臂梁,利用二结点梁单元进行离散化建模,在计算出结构所受外部时变载荷的基础上,建立了风力机结构动力学运动方程。通过研究叶片的空气动力阻尼,得到了叶片在不同模态下的阻尼比,集成到叶片结构动力响应计算过程中,以获得更精确的动力响应仿真结果。运用 Newmark 法和模态叠加原理对风力机叶片和塔架的动力响应进行计算, 编制了相应的计算程序。对于叶片,分析了转速、桨距角、方位角和结冰对叶片固有动力特性的影响,并考虑了由于叶片旋转所产生的离心刚化作用和气动阻尼作用对叶片动力响应的影响;对于塔架,考虑了塔顶风轮和机舱作为质点与塔架耦合后的塔架固有动力特性,并考虑了来自风轮的气动阻尼对塔架动力响应的影响。以 MW 水平轴风力机为例,仿真了其在湍流风场作用下的发电工况,获得了风力机结构动力响应和动态载荷。将本文计算结果和商业软件 GH Bladed 的计算结果进行了对比,取得了一致的仿真结果,验证了本文模型的可靠性。关键词: 风力机;结构动力学;动力响应;离心刚化;气动阻尼汕头大学硕士学位论文 Abstract II Abstract The modern large horizontal axis wind turb ine usually undergoes large vibration and deflection, which can not only cause structure add itional stress and affect structure strength, but also affect aerodynamic performance. The intera ction between aerodynamics and structure will cause fluid-solid coupling process. So it’s impor tant to predict the stru cture dynamic response in the time-varying load. The paper firstly analyzes the blade aerodynamic performance, presents the blade element- momentum theory and its different correct met hods, also analyzes the blade dynamic stall and dynamic inflow in order to calculate the rotor dynamic aerodynamic performance accurately. The analysis of the HAWT structure time-varyi ng load provides the foundation for calculating the structure dynamic response. In order to obtain the blade and tower dynami c response to the time-va rying load, the blade and tower of horizontal axis wind turbine ar e both simplified as a variable cross-section cantilever and discretely modelled by applying two-node beam element. Through establishing the structure dynamic equation and calculating th e time-varying loads on the blade