褶皱结构对蜻蜓后翅的气动特性影响分析

褶皱结构是否能对蜻蜓后翅气动性能产生正面的影响,对蜻蜓后翅气动性能的影响是否与雷诺数(Re)相关。建立接近真实蜻蜓后翅的三维蜻蜓后翅褶皱模型和拥有同样外形的三维平板模型,利用计算流体力学方法分别计算两个模型在不同Re、不同攻角(α)下滑翔飞行时的气动特性。结果表明:褶皱结构的存在会明显提高蜻蜓后翅的升力,但是同时也会增大其阻力;不同Re情况下,褶皱结构对蜻蜓后翅气动性能的影响不同,当Re=1 000,α=0°～25°时,蜻蜓后翅的气动效能始终略优于三维平板;褶皱结构对蜻蜓后翅气动特性的影响与α也相关,α较大时蜻蜓后翅的气动效能略优于三维平板。

Aerodynamic Effects of Dragonfly Hindwing at Gliding Flight at Different Reynolds Numbers

In order to study aerodynamic performance of the dragonfly wing at gliding flight at different Reynolds numbers, a three-dimensional model of the dragonfly hindwing with corrugation and a three-dimensional flat plate with the same shape of the dragonfly hindwing are established. We studied aerodynamic effects of corrugation at gliding motion using the method of computational fluid dynamics, in the Reynolds number range of 1000 to 10000 and angles of attack changing from 0° to 25°(with an interval of 5°).The finding are as follows:(1)The effect of corrugation is to increase both lift and drag to varying degrees;(2)The aerodynamic effect of wing corrugation might be Reynolds numbers dependent. While Re=1000,aerodynamic performance of the dragonfly hindwing is slightly better than the flat plate over the entire range of parameters tested; (3) The effect of corrugation depends on the angle of attack, while at a higher angle of attack, aerodynamic performance of the dragonfly hindwing is slightly better than the flat plate.