《水平轴风力机叶片的多目标优化设计及结构动力学分析(优化气动和载荷12)》由会员分享,可在线阅读,更多相关《水平轴风力机叶片的多目标优化设计及结构动力学分析(优化气动和载荷12)(94页珍藏版)》请在金锄头文库上搜索。
1、汕头大学硕士论文 Abstract摘要本文针对国家科技支撑计划子课题“风电机组叶片气动优化设计和结构动力分析”, 探讨了能满足风力机叶片气动、结构和稳定性要求的多目标优化方法。通过对不同展向上翼型的相对厚度、弦长等外形参数的优化计算,得到了能使功率利用系数Cp值达到预定目标的气动优化设计结果;考虑结构和制造工艺性要求,修正了气动外形。并对优化后的叶片进行了载荷计算,使叶根载荷得到了降低,并对其进行强度分析。论文的主要内容如下:综合考虑叶片气动性能和载荷情况,即除要保证风力机叶片有良好的气动外形之外,还要兼顾稳定性和结构强度等性能指标,对叶片的整体性能进行多目标优化。叶片的优化设计,是以叶片各展
2、向截面的相对厚度、弦长和扭角为设计变量,建立了多目标优化的数学模型。基于遗传算法思想并利用MATLAB软件,实现了叶片的多目标优化设计。同时,采用该方法对1.5MW风力机叶片进行了优化设计,并与已运行的某商用机型做出对比,以验证该方法的有效性。在FLUENT软件的GAMBIT前处理模块中建立了叶片的三维实体模型,并将建好的风力机叶片模型导入ANSYS软件中进行了模态分析,针对玻璃钢/复合材料的特点进行单元网格划分、施加一定的约束,得到前十阶振型的频率和振型。同时,研究了科里奥利力对叶片模态分析的影响。基于GL坐标系,计算了风力机稳态下的气动力、重力、离心力;以1.5MW水平轴风力机的叶片为例,
3、借助于Bladed for Windows软件,计算了叶片上关键截面处的载荷。并找出根部的最大载荷,在ANSYS软件中进行有限元分析,得出此载荷作用下的变形图及应力云图。安全系数确定后,对其进行静强度校核。根据IEC61400-1:1999标准,拟定了1.5MW水平轴风力机运行的各种工况,分别计算出各工况下的载荷,在Bladed for Windows软件的后处理模块中提取出最大载荷及其所对应的工况,可据此对风力机叶片的强度进行校核。关键词:风力机叶片;多目标优化; 结构动力学;模态分析;强度校核AbstractThis paper belongs to National Key Techno
4、logies R&D Program - Aerodynamic optimization design and structure dynamic analysis of wind turbines blade. To meet the requirements of the aerodynamics, structure and stability, multi-objective optimization methods of HAWT blades have been developed. Through optimizating the shape parameters in the
5、 different distance from blade root, such as, relative thicknesses, chord lengths and torsion angles of the airfoils, the aerodynamic design optimization results that a power utilization factor Cp reached the intended target could be got. Finally, considering some requirements of structure and manuf
6、acturing process, aerodynamic shape was revised. After optimizing HAWT blades, load calculations were carried through to decrease the loads of the root. And on the basis of loads calculation, there was strength analysis on HAWT blades. The main contents were as follows:The design objective was to fi
7、nd blade shape such that maximizing power utilization factor as well as decreasing the loads. Considering aerodynamic performance and loads, multi-objective optimization of the blade was carried to take care of the stability and structure strength indicators, in addition to ensure a good performance
8、 of wind-turbine rotor blade,. Blade optimization design was that relative thicknesses, chord lengths and torsion angles in different sections, were regarded as design variables, and a multi-objective optimization mathematical model was established. Based on the genetic algorithms with the use of MA
9、TLAB software, a multi-objective optimization blade design was achieved. At the same time, this method was used to optimize and design a 1.5 MW wind turbine blade. Compared with some commercial blade model, the effectiveness of the method had been verified. GAMBIT, the pre-processing module of FLUEN
10、T software, was used to establish a 3D model of the blade, and the wind-turbine rotor blade model was completed into ANSYS software to modal analysis. In view of the characteristics of fiber reinforces plastic, a mesh was built to carry out the model analysis, and the first 10 orders of the vibratio
11、n frequencies and mode shapes were obtained, by imposing certain bound on the root of blade. Meanwhile, the impact of Coriolis on Modal Analysis of the blade was researched.Based on GL coordinates, aerodynamics, gravity and centrifugal force on the wind turbine were calculated. With the help of Blad
12、ed for Windows software, a 1.5 MW horizontal axis wind turbine blade was taken for example to calculate the loads of the root, and the maximum load of the root were identified. The finite element analysis was done in ANSYS software, and the deformation and stress cloud figures under limit load were
13、got. After determining the safety coefficient, the static strength check was completed. According to IEC61400-1:1999 standard, the various working conditions of 1.5 MW horizontal axis wind turbine were studied and the loads under various conditions were calculated, the maximum load and the correspon
14、ding condition were extracted from the post-processing modules in Bladed for Windows software, with which the strength of wind turbine blade cloud be checked.Keywords: Wind turbine blade, Multi-objective optimization, Structure dynamics, Mode analysis, Strength check87汕头大学硕士论文 第一章 引言 符号说明空气密度风速相对风速实
15、度风轮角速度风轮直径轮毂直径风轮扫掠面积叶片数叶片截面弦长尖速比轴向速度诱导因子切向速度诱导因子翼型升力系数翼型阻力系数风轮功率系数风轮推力系数叶素升力叶素阻力叶素轴向力叶素周向力叶素转矩Prandtl叶尖损失因子风轮转矩风轮功率来流角攻角截面扭角攻角的叶栅效应修正方位角叶轮倾斜角叶轮锥角偏航角电机效率传动效率第个截面的到叶片根部的距离第个截面的翼型厚度运行维护成本制造生产成本精度要求有限元节点加速度有限元节点速度有限元节点位移有限元节点所作用的外力矢量单层板的展向弹性模量径向弹性模量剪切弹性模量()泊松比材料的许用应力实际计算出的最大应力材料安全系数轮毂处风速风剪指数目录摘要IAbstractII符号说明IV目录VI第一章 引言11.1选题背景及意义11.1