最优S型小翼影响近尾迹流动的PIV测试

PIV Experiment on the Effect of Near Wake Using Horizontal Axis Wind Turbine With Optimal Ogee Tip Vane

在水平轴风力机叶尖添加结构合适的小翼,可以改变风轮表面的压力分布,提高功率输出,并调整风轮的动频曲线走势,改善其结构动态特性。本文提出S型叶尖小翼结构形式,采用5因素5水平的正交实验方法,找到在不同尖速比下均具有较好功率放大效果的最优叶尖小翼结构。采用轴编码器定位周期采样技术,在直流式低速风洞开口段对动态旋转风力机添加最优S型小翼和不添加小翼时的近尾迹流动进行了对比PIV测试。结果表明,结构合适的S型叶尖小翼可以打散从风轮叶尖脱落的叶尖涡结构,在测试方位面内形成多个涡量集中区域,而且使叶尖涡内高涡量区域减小,降低叶尖涡的强度,改善风轮的空气动力学特性,提高风轮的功率系数。

The horizontal axis wind turbine with the structure appropriate tip vane can change the pressure distribution of blade surface, improve power output, adjust the rotor dynamic frequency curve, and improve the structural dynamic characteristics of rotor. This paper elaborates the design of the ogee tip vane. The tip vane with preferable power augmentation effect was found by L25 experiment. The PIV measure of near wake dynamic flow of the rotating wind turbine with ogee tip vane and without tip vane was carried out using axis-coder phase-locked periodic sampling technology at wind tunnel opening. The experimental results show that the tip vane can diffuse and weaken the tip vortex, therefore, can improve aerodynamic characteristics and power coefficient of rotor.