Flexible-Membrane Airfoils at Low Reynolds Numbers
Flexible-Membrane Airfoils at Low Reynolds Numbers
复制标题
DOI：
10.2514/1.36438
复制
发表时间：
2008-09-01
影响因子：
2.2
通讯作者：
Murphy, Jeffery T.
中科院分区：
文献类型：
--
作者：
Hu, Hui;Tamai, Masatoshi;Murphy, Jeffery T.
进行了一项实验研究，以评估使用柔性薄膜翼型/机翼在低雷诺数的微型飞行器的应用相比，使用传统的刚性翼型/机翼的好处。除了测量作用在柔性薄膜翼型/机翼上的气动力外，还使用高分辨率粒子图像测速系统进行流场测量，以量化柔性薄膜翼型/机翼周围的涡流和湍流结构的瞬态行为，从而阐明相关的基本物理。气动力测量结果表明，柔性薄膜翼型可以提供更好的气动性能相比，他们的刚性对应在低雷诺数。翼型薄膜蒙皮的柔性（或刚性）对其气动性能有很大的影响。粒子图像测速测量阐明了柔性膜翼型可以改变它们的弯度（即，横截面形状）来自动调整来流以平衡翼型件的上表面和下表面上的压力差，从而抑制翼型件上表面上的流动分离。同时，柔性膜蒙皮的变形被发现会导致显著的翼型后缘偏转（即，将翼型后缘从其原始设计位置提升），这导致柔性膜翼型的有效迎角减小，从而延迟翼型在大迎角时的失速。柔性薄膜翼型的柔性薄膜蒙皮的非均匀展向变形被发现显著地影响柔性薄膜翼型周围的涡流和湍流结构的特性。
An experimental study was conducted to assess the benefits of using flexible-membrane airfoils/wings at low Reynolds numbers for micro air vehicle applications compared with using a conventional rigid airfoil/wing. In addition to measuring aerodynamic forces acting on flexible-membrane airfoils/wings, a high-resolution particle image velocimetry system was used to conduct flowfield measurements to quantify the transient behavior of vortex and turbulent How structures around the flexible-membrane airfoils/wings to elucidate the associated underlying fundamental physics. The aerodynamic force measurements revealed that flexible-membrane airfoils could provide better aerodynamic performance compared with their rigid counterpart at low Reynolds numbers. The flexibility (or rigidity) of the membrane skins of the airfoils was found to greatly affect their aerodynamic performance. Particle image velocimetry measurements elucidated that flexible-membrane airfoils could change their camber (i.e., cross-sectional shape) automatically to adapt incoming flows to balance the pressure differences on the upper and lower surfaces of the airfoils, therefore suppressing How separation on the airfoil upper surfaces. Meanwhile, deformation of the flexible-membrane skins was found to cause significant airfoil trailing-edge deflection (i.e., lift the airfoil trailing edge up from its original designed position), which resulted in a reduction of the effective angles of attack of the flexible-membrane airfoils, thereby delaying airfoil stall at high angles of attack. The nonuniform spanwise deformation of the flexible-membrane skins of the flexible-membrane airfoils was found to significantly affect the characteristics of vortex and turbulent flow structures around the flexible-membrane airfoils.