小翼羽掠角对机翼增升效果的影响  

The effect of alula’s sweep angle on wing lift augmentation

作　　者：唐钰涵 王将升 王晋军[1] TANG Yuhan;WANG Jiangsheng;WANG Jinjun(Key Laboratory of Fluid Mechanics,Ministry of Education,Beihang University,Beijing 100191,China)

机构地区：[1]北京航空航天大学流体力学教育部重点实验室,北京100191

出　　处：《空气动力学学报》2024年第2期76-84,I0002,共10页Acta Aerodynamica Sinica

基　　金：国家自然科学基金(12102024,11721202)。

摘　　要：鸟类会通过抬起其翅膀前缘3至4根长度较短的羽毛(小翼羽)来抑制失速和增加升力,并根据不同飞行状态改变小翼羽与翅膀之间的掠角。为应对大迎角下的机翼失速问题,本文结合风洞测力和粒子图像测速实验研究了小翼羽掠角对机翼增升效果的影响。风洞测力实验结果表明,相比于无前掠的小翼羽,适当前掠的小翼羽对机翼的增升效果更好且不会增加机翼阻力。平面粒子图像测速和体视粒子图像测速实验表明,适当的前掠角能够增强小翼羽产生的前缘涡的强度,并扩大前缘涡增升的有效机翼迎角范围,最终导致适当前掠的小翼羽对机翼的增升效果更好。Birds deploy several short feathers called alula at the leading edge of wings to suppress stall and increase lift.The sweep angle between the alula and the wing is adjusted according to different flight states.The effects of the alula sweep angle on the aerodynamic performance of the rectangular wing are therefore investigated by utilizing force measurement and particle image velocimetry.Compared to an alula with a zero sweep angle,an alula with an appropriate non-zero forward sweep angle can increase the lift and does not introduce extra drag,thus improves considerably the aerodynamic performance.The underline mechanism is revealed by the flow fields measured by planar and stereo particle image velocimetries,which demonstrate that the alula with an appropriate non-zero forward sweep angle enhances the strength of the leading edge vortex over the wing and broadens the range of angle of attack in which the leading edge vortex can increase the lift.

关 键 词：小翼羽 掠角 风洞 粒子图像测速 前缘涡 增升 流动控制 仿生流体力学 实验 

分 类 号：O355[理学—流体力学]