不同叶尖损失模型的风力机气动性能分析

ANALYSIS OF AERODYNAMICS OF WIND TURBINE BASED ON DIFFERENT TIP LOSS MODELS

基于叶素动量理论,引入风力机叶片叶尖损失,利用Matlab优化工具箱计算轴向和周向干扰因子;采用多项式拟合函数和插值函数计算升力系数和最佳攻角等参数,得到叶片外形参数及功率利用系数。深入研究分析了Wilson叶尖损失模型和Shen叶尖损失模型在风力机气动性能计算上的异同。得出:在高尖速比工况时,Shen模型设计出的叶片弦长在靠近叶尖部位呈现反增趋势;在计算功率利用系数时,Shen模型在低尖速比和高尖速比工况下计算出的功率利用系数小于Wilson模型的值,更接近实际。

Based on blade element moment theory and introducing the concept of tip loss of wind turbines, the axial and angular induction factors were calculated with the optimization toolbox of Matlab. Lift coefficients and attack angles in the best condition were computed by using polynomial fitting and interpolation functions, then the outline parameters of blades and power coefficients were obtained. The similarities and differences of calculating aerody- namics of wind turbine were analyzed deeply with Wilson and Shen methods. It is found that there are no significant differences on the outline design between these two models except an unexpected increase in the chord distribution in the tip regions with Shen model. The power coefficients at low and high A of Shen are relatively lower than Wilson model, predicting results slightly better than Wilson.