风力机叶片优化设计及模态分析研究

Research on optimum design and modal analysis of horizontal-axis wind turbine blade

以叶素-动量理论为基础,对1.0 MW风力机叶片进行气动外形设计。采用Wilson方法建立叶片外形设计数学模型,模型考虑了叶片梢部损失、根部损失和轴向、周向干扰因子对叶片空气动力学性能的影响,以MATLAB为工具实现对各外形参数的求解,并对计算结果进行线性化修正处理,获得了优化的弦长和扭角。通过坐标变换原理将翼型二维离散数据点转换成叶片三维空间坐标点,另外在变换坐标过程中结合图形学,将坐标的旋转变换转化到绘图过程中实现。绘制叶片各截面的空间样条曲线,基于Pro/E的自由曲面造型功能对风力机叶片进行建模,并采用ANSYS软件对叶片进行模态分析,得到了叶片的固有频率及振型,为风轮动力学分析奠定了基础。

Aerodynamic shape of blade for 1.0 MW horizontalaxis wind turbine is designed on basis of Pituitrin-Momentum Theory. It adopts Wilson method to establish blade shape design mathematical model. Blade tip loss ,root damage and the effect of axial and circumferential interference factor on the aerodynamic properties of blade are taken into account. The parameters of shape for blade are calculated by MATLAB, and the results are revised by linear correction method. Two-dimensional airfoil coordinate is converted into three-dimensional coordinate of the blade on basis of transformation theory of discrete data points. In addition, graph- ics are integrated into coordinate transformation,enabling coordi- nate rotation transformation to be realized in the process of draw- ing. The cross section curves of the blade are drawn, and then the blade solid model is established on basis of free surface modeling function of Pro/E. Modal analysis of the blade is made by ANSYS, which can get natural frequency of blade and mode of vibration. It is the basis for dynamics analysis of wind rotor.