基于参数化建模的风力机叶片结构分析及优化设计

发布时间：2018-01-13 01:13

本文关键词：基于参数化建模的风力机叶片结构分析及优化设计　出处：《重庆大学》2014年硕士论文　论文类型：学位论文

【摘要】：近年来，“能源危机”对人类的影响越发凸显，可再生能源由此得到快速发展。风能，作为一种可再生的“绿色能源”已席卷全球，，被世界各国予以极大的关注与重视，都把运用风能作为能源短缺的突破口。中国作为能源消费大国，政府亦大力支持风电行业的发展，但由于中国风电起步较晚且国外把风电核心技术作为企业最高机密，中国风电因此大大落后于风电发达国家，大型风电设备，尤其是风机叶片主要依靠进口。而风机叶片由于其直接捕获风能，良好的气动性能、较高的质量保证是风机稳定运行的前提。本文提出了“基于参数化建模的风力机叶片结构分析及优化设计”的研究课题。本文根据某一现有风力机叶片，重点对其气动性能，结构分析及优化设计进行了研究，取得了如下成果： ①风机叶片气动载荷模型基于叶素-动量理论建立，其中考虑叶尖损失修正模型的影响，更加精确的确定轴向诱导因子和周向诱导因子。基于GL2010标准，分析了风力机所受到的各种载荷如：重力载荷、离心力载荷及空气动力载荷等，研究了风力机工作的载荷工况和设计工况，通过BLADED建立了风力机整机模型，其包括叶片、翼型、叶轮、塔架、动力传动链、机舱和控制等模块，通过计算得到风机在各种工况下的截面载荷分布，从中筛选出截面载荷最大极端工况，从而得到叶片各截面处的极限载荷，其为叶片后续结构分析及优化奠定基础。 ②在全面探究了叶片结构及铺层方式的基础上，提出了叶片弦长、扭角和相对厚度的集成表达，通过叶片三维形状参数表达式得到叶片空间三维坐标，由MATLAB编程并结合ANSYS二次开发由底至顶建立了叶片参数化几何模型，根据叶片铺层材料及铺层方式全面建立了叶片有限元力学模型，通过计算叶片质量及重心位置且与实验结果比较验证了该模型建立的可靠性。 ③通过叶片模态分析得到叶片低阶固有频率及振型，其与实验结果相差不大，分析了该叶片在正常运行过程中是否发生共振现象。由于叶片由复合材料构成，而复合材料表现出各向异性，且叶片主要由翼面、叶根、主梁和腹板等关键部位组成，各部位材料及铺设方式不同，因此在校核叶片强度时应根据需要分别校核上述部位。叶片刚度尤为重要，其表明叶片受力变形后是否与塔架发生碰撞。 ④提出以材料厚度，叶片结构参数作为优化变量，叶片质量作为优化目标，在保证叶片强度和叶尖位移的前提下建立了叶片结构优化的数学模型，通过MATLAB并结合ANSYS编程，运用改进的粒子群算法进行寻优，经数次迭代后得到既满足性能要求，质量又较轻的叶片。该研究对叶片结构的优化及改造具有重要的现实指导意义，并为叶片的气动、结构一体化设计提供可能。
[Abstract]:In recent years, the impact of "energy crisis" on human beings has become more and more prominent, and renewable energy has been rapidly developed. Wind energy, as a renewable "green energy", has swept the world. By the world to pay great attention and attention to the use of wind energy as a breakthrough. China as a large country of energy consumption, the government also vigorously support the development of wind power industry. However, due to the late start of wind power in China and the core technology of wind power as the top secret of enterprises abroad, wind power in China lags far behind the developed countries and large-scale wind power equipment. Especially the fan blade mainly depends on the import, and the fan blade has good aerodynamic performance because of its direct capture of wind energy. High quality assurance is the premise of stable operation of wind turbine. This paper puts forward the research topic of "structural analysis and optimization design of wind turbine blade based on parametric modeling". The aerodynamic performance, structure analysis and optimization design are studied in detail. The results are as follows: 1. The aerodynamic load model of fan blade is established based on the theory of blade element and momentum, and the influence of blade tip loss correction model is taken into account. The axial and circumferential induction factors are determined more accurately. Based on the GL2010 standard, various loads such as gravity load, centrifugal force load and aerodynamic load on the wind turbine are analyzed. The load and design conditions of the wind turbine are studied, and the wind turbine model is established by BLADED, which includes blade, airfoil, impeller, tower, power transmission chain, engine room and control module. By calculating the cross-section load distribution of the fan under various working conditions, the maximum extreme condition of the cross-section load is selected, and the ultimate load at each section of the blade is obtained. It lays a foundation for the following structure analysis and optimization of blade. 2 on the basis of exploring the blade structure and layering mode, the integrated expression of blade chord length, torsion angle and relative thickness was put forward, and the three-dimensional coordinate of blade space was obtained by the blade three-dimensional shape parameter expression. The parametric geometric model of blade was established by MATLAB programming and combined with ANSYS secondary development from bottom to top, and the finite element mechanical model of blade was established according to the lamination material and layering method. The reliability of the model is verified by calculating the mass and center of gravity of the blade and comparing with the experimental results. (3) the low-order natural frequency and mode shape of the blade are obtained by modal analysis of the blade, which is not different from the experimental results. The resonance phenomenon of the blade is analyzed during the normal operation, because the blade is composed of composite material. The composite material shows anisotropy, and the blade is mainly composed of wing surface, leaf root, main beam and web. The materials and laying methods of each part are different. Therefore, when checking the strength of the blades at school, the above parts should be checked separately according to the need. The stiffness of the blades is particularly important, which indicates whether the blades collide with the tower after deformation. (4) taking material thickness, blade structure parameter as optimization variable and blade quality as optimization objective, the mathematical model of blade structure optimization is established on the premise of ensuring blade strength and tip displacement. Through MATLAB and ANSYS programming, the improved particle swarm optimization algorithm is used to find the optimization. After several iterations, it can meet the performance requirements. The research has important practical significance for the optimization and transformation of blade structure and provides the possibility for the aerodynamic and structural integration design of the blade.
【学位授予单位】：重庆大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM315

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