摘要
蜻蜓翅膀具有独特的褶皱结构,其横截面在扑翼飞行中常呈现弯曲变形.本文设计了具有弯度的褶皱翼型,并综合考虑弯度大小及分布的影响;基于Fluent软件,采用重叠网格方法对其扑翼前飞的气动性能进行分析.首先,与平板褶皱翼相比,正弯度褶皱翼可以显著提高升力,在对弯曲大小和分布的合理设计下,如m=4％,p=0.2时,可实现在扑翼中同时提高升力和推力.其次,弯曲褶皱翼型的升力随着扭转角的增加而增加,但是较大扭转角会降低推力,此时可通过后移最大弯曲位置改善推力.因此,在特定条件下,合适的弯度大小及分布可以较大幅度地改善褶皱翼型的气动力性能.
Abstract
The corrugated dragonfly wings are always deformed with cambered sections during flight.To study the aerodynamic performance of dragonfly wings in forward flight,two dimensional corrugated airfoils are designed,considering the heights and chordwise location of maximum camber.Then the aerodynamic forces are calculated in Fluent software by the overlapping grid method.Firstly,lift of the corrugated airfoils with positive camber are significantly improved compared with flat airfoil.Both the lift and thrust can be enhanced when the airfoil is well-designed with camber such as m=4％and p=0.2.Secondly,the lift of cambered airfoils is increased while the trust will be decreased when the torsional angle is enlarged in flapping.Moving the position of maximal camber height to the trailing edge can help to improve the trust at high torsional angle.As a result,the aerodynamic performance of corrugated airfoil can be greatly improved by introducing the camber with well-designed height and position.
基金项目
国家自然科学基金(12002200)
深圳市基础研究重点项目(JCYJ20210324120212034)
NETL
NSTL
万方数据