摘要:
介绍了安装有后移式微型后缘装置(Rearward Mini-TED)的NACA23012翼型流场结构的低雷诺数风洞实验结果。实验采用PIV技术采集了不同迎角时翼型周围的速度分布,测量了后缘附近 Mini-TED周围的详细涡旋结构,并与NACA23012原型翼型周围流场进行比较分析,以研究该 Mini-TED对翼面流动分离特性造成的影响,本实验以弦长为特征量的雷诺数为Re≈1.3×105。实验结果显示,Mini-TED对上翼面的流动分离有明显的抑制作用,尤其在较大迎角时更为有效,并且上翼面流速均高于对应迎角时原型翼型的翼面速度;下翼面流动在Mini-TED前方形成局部的低速区,造成静压升高,同时 Mini-TED 上方观察到对涡结构,形成低压区,二者共同作用的结果将导致后缘产生附加升力,增加翼型的低头力矩。上下翼面间的速度差比原型翼型有所增加,使翼型获得更高的升力。
Abstract:
The wind tunnel experimental results of flow structures of a NACA23012 airfoil mounted with a rearward Mini-TED for low Reynolds number situations are introduced in this pa-per.The PIV technique was applied to capture the velocity fields around the airfoil for different angle of attack,and the detailed vortex structures near the trailing edge were measured as well. The velocity measurement results are compared with those of NACA23012 prototype airfoil,so as to investigate the influence of the Mini-TED on the flow separation characteristics above the airfoil surface.The Reynolds number is Re≈1.3×105 based upon the chord length of the airfoil. The results show that the flow separation on the suction surface of the airfoil,especially for the case of larger angle of attack,is obviously depressed due to the installation of Mini-TED,and the flow speed on the suction surface is much higher than that of NACA23012 prototype airfoil.A low speed region is locally formed in front of the Mini-TED,which leads to the increase of static pressure.Meanwhile,a double-vortex structure with low pressure is observed behind the Mini-TED.The resulting pressure difference causes the extra lift increment near the trailing edge of the airfoil,and the pitching moment is increased as well.The velocity differences between the suction surface and the pressure surface of airfoil with the Mini-TED are higher than those of the NACA23012 prototype airfoil,which can contribute to the increment of lift force.
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