昆虫翅平面形状和展弦比对其气动性能的影响

应用计算流体力学的方法研究昆虫翅膀平面形状和展弦比对其拍动运动时气动力的影响.选取了10种具有代表性的平面形状和展弦比差别较大的昆虫翅膀作为研究对象.这10种昆虫分别是果蝇、大蚊、蜂蝇、食蚜蝇、瓢虫、熊蜂、蜜蜂、草蜻蛉(前翅)、鹰蛾 和蜻蜓 (前翅).研究结果表明:翅膀面积的二阶矩折合半径越大其气动力越大,当使用翅膀面积的二阶矩折合半径处的速度作为参考速度时,翅膀平面形状对无量纲气动力的影响很小.当翅膀展弦比有较大变化(从2.8增大到5.5)时,气动力系数只有很小的变化.流动的三维效应减弱和部分前缘涡(LEV,Leading-Edge Vortices)的脱落,这两种效果相互抵消,导致气动力系数变化不大. 

Effects of wing planform on aerodynamics force production of stroking model insect wing

The effects of wing planform (shape and aspect ratio) on the aerodynamic force production of model insect wings in stroking motion were investigated, using the method of computational fluid dynamics. Ten respective insect wings were considered, they were the wings of fruit fly, cranefly, dronefly, hoverfly, ladybird, bumblebee, honeybee, lacewing (forewing), hawkmoth and dragonfly (forewing).The main results are as following. The force will be increased as the radius of the second moment of wing area is increased, but it has only minor effects on the force coefficients when the velocity at the radius of the second moment of wing area is used as the reference velocity. The force coefficients vary slightly, when aspect ratio increasing from 2.8 to 5.5. The reduction of 3-dimensional flow effects and the shedding on part of the leading-edge vortices (LEV) cancel each other, resulting in only minor change of the force coefficients.