【作者】 盛杰；

【导师】 王军；

【作者基本信息】 华中科技大学 ， 流体机械及工程， 2011， 硕士

【摘要】 本文利用了CFD流体计算软件,以2KW小型定桨距水平轴风力机为研究对象,对风力机专用翼型以及风力机风轮的气动性能进行了数值模拟研究。机翼翼型的选择好坏直接影响风力机的损失大小,直接影响叶轮的空间结构。论文在对相同厚度的翼型优化的基础上,展开设计风力机,对三维模型CFD分析,给出相应分析结果。选取三种具有相同相对厚度(相对厚度为21%)但形状不相同的常用风力机翼型NACA0021,NACA63421和NREL-S809(简称为S809),进行二维建模和网格划分,对比三种翼型形状上的差异,并利用Fluent取雷诺数等于5.5×105时对其空气动力学性能进行数值模拟和分析,得到不同攻角下三种翼型的升阻力系数和升阻比,并和实验数据进行对比验证。通过数值结果相互比较分析,给出同相对厚度风力机翼型气动性能。以Wilson理论为基础,对2KW小型定桨距风力机叶片进行了气动设计。在此过程中,考虑了叶尖、叶根损失和轴向、周向干扰因子对叶片最佳性能的影响。然后基于Pro/Engineer三维造型软件实现了风力机叶片及整个风轮实体模型的三维建模。最后,在额定工况和七个非额定工况下,对整个风力机风轮流场进行了数值模拟,计算得到不同风速下风力机的功率和效率。验证了本文所采用的优化设计方法和数值模拟方法的可靠性和有效性,并对各工况下的风力机风轮叶片的压力和速度分布流场进行了分析,并讨论了三维旋转效应对流动特性的影响。更多还原

【Abstract】 This article focuses on 2KW small fixed pitch horizontal axis wind turbine using the CFD software to explore the aerodynamic performance of wind turbine special airfoils and wind wheel regarding to numerical method. The energy lost and space structure of wind turbine is influenced by the performance of the airfoils.The following areas are being covered and an efforts are made to investigate in this study.Three different kinds of airfoils with the similar relative thickness of 21% were choosen,the name of the blades are NACA0021,NACA63421 and NREL-s809. 2D caculated models of airfoils are being built and compared with each other. With the help of Fluent software,the aerodynamic performance of the airfoils is simulated and analyzed when the Renald Number is 5.5×105,comparison between the simulated data and the experiment data is carried out in order to verify the reliability of aerodynamic numerical simulation. The simulation and analysis is helpful to understand the aerodynamic performance and character of aerofoils of wind turbine.Numerious factores need to be considered when the 2KW small fixed pitch wind turbine are being built, for instance the tip of blade loss、the root of blade loss、the axial and circumferential factor is also vital to the construction of 2KW small fixed pitch wind turbine and has the effects on the performance of the blade in order to optimize the function. Thanks to the Pro/ENGINEER 3D modeling software and the widely application and implenmentation, the target of building three dimensional solid model of the wind turbine blades and rotor are realized.At last, if different conditions applied ,the statistics generated in numerical method will vary in wind turbinr power and efficiency. Therefore we have to use software Fluent in numerical simulation for wind turbine at rated operating condition and five other conditions to get the the different numbers respectively. In conclusion, it can be verified that the optimal design method and numerical simulation are reliable and valid. Meanwhile the analysis of pressure and velocity distribution of the wind wheel blades at rated operating conditions were given and the likely effects of the three dimensional rotationalon the flow characteristics.更多还原