研究了两种改善风力机叶型气动性能的流动控制技术,分别对风力机专用S809翼型和较大升阻比的FX 60-100翼型进行应用研究.首先,通过在叶型前缘加装流动偏转器,研究流动偏转器对叶型流动分离的控制效果.并采用多岛基因算法,对流动偏转器进行多参数优化.结果表明:流动偏转器可以有效控制叶型的失速特性,推迟失速攻角和增加升力;基因优化算法能更大地提升流动偏转器的控制效果.其次,基于对风力机叶尖旋涡和尾涡特征以及叶片表面压力分布的分析,在叶片尖部加装不同倾斜角的旋涡扩散器控制叶尖涡.结果表明:涡扩散器能够提高叶尖涡涡核的总压,削弱其旋涡强度,使风力机尾流旋涡耗散更快,从而可以减小噪声,提高叶片效率.
Two techniques that improve the aerodynamic performance of wind turbine airfoils were described.The airfoil S809,often used for wind turbine design,and the airfoil FX 60-100,having higher lift-drag ratio,were selected to verify the flow control techniques.The flow deflector,fixed at the leading edge,was employed to control the boundary layer separation on the airfoil at high angle of attack.The multi-island genetic algorithm was used to optimize the parameters of the flow deflector.The results indicate that the flow deflector can suppress the flow separation,delay stall and enhance the lift.In the second part of this paper,the characteristics of the blade tip vortex,wake vortex and the surface pressure distributions of blades are analyzed.The vortex diffuser,set up at the blade tip,was employed to control the blade tip vortex.The results show that the vortex diffuser can increase the total pressure coefficient of the core of the vortex,decrease the strength of blade tip vortex,lower the noise and improve the efficiency of the blade.