基于多目标遗传算法的垂直轴风力机专用翼型优化设计

OPTIMAL DESIGN OF VERTICAL AXIS WIND TURBINE SPECIAL AIRFOIL BASED ON MULTI-OBJECTIVE GENETIC ALGORITHM

为提升垂直轴风力机翼型综合气动性能,建立针对多运行工况的翼型优化设计方法。采用CST参数化方法表征翼型几何外形,通过优化的拉丁超立方抽样方法进行空间采样,利用CFD方法计算翼型气动力,并建立径向基函数神经网络代理模型,以翼型小攻角下升力和失速攻角下升阻比最优为设计目标,采用多目标遗传算法在代理模型上进行寻优,获得适用于垂直轴风力机的专用翼型以提高其在不同尖速比下的旋转力矩。对风力机常用翼型NACA0018进行优化,结果表明:以翼型失速攻角和最大升阻比攻角为优化目标,不仅提高了单翼型的升力系数与升阻比,而且将优化翼型应用于垂直轴风力机时还可提升使整机力矩系数。

In order to improve the comprehensive aerodynamic performance of vertical axis wind airfoil,an airfoil optimization design method for multiple operating conditions was established.The CST parameterization method is used to characterize airfoil geometry shape.Through optimizing the Latin hypercube sampling method for space sampling,CFD method is used to calculate airfoil aerodynamic force,and establish the radial basis function(RBF) neural network surrogate model.Taking the optimal of airfoil lift under the small angle of attack and lift-to-drag ratio under small angle of attack as the optimal design target,adopts the multi-objective genetic algorithm optimization on the surrogate model,so as to obtain suitable dedicated airfoil for vertical axis wind turbines to improve its rotation torque under different tip speed ratios.Through optimization of the common airfoil NACA0018 for wind turbine,the results show that the lift coefficient and lift to drag ratio of a single airfoil are not only improved by taking the small angle of attack and the maximum angle of attack of lift to drag ratio as the optimization objectives,but also the torque coefficient of the whole airfoil can be improved when the optimized airfoil is applied to the vertical axis wind turbine.