三铰扑翼建模及数值计算

Modeling and numerical computation of three hinge flapping wing

为研究鸟类翅膀展向变形对扑翼气动特性的影响,基于对鸟类翅膀变形的观察,分别用动静法和拉格朗日方程建立三铰扑翼的数学模型,并利用数值计算研究该模型.结果表明:使用NACA0004作为截面的三铰扑翼在对称扑动时能够产生净升力;随着中翼弹性系数比的增大,周期平均升力因数增大,但周期平均阻力因数不存在单调性;三铰扑翼比双铰翼的周期平均升力因数明显小;随着外翼弹性系数比的增大,周期平均升力因数和周期平均阻力因数也不存在单调特性.

To study the effect of spanwise deformation of bird wing on the aerodynamic characteristics of flapping wings, the kinematics model of three hinge flapping wing is built separately by dynamic static method and Lagrange equation based on the observation of bird wing deformation, and the model is studied by numerical computation. The results show that the three hinge flapping wing, for which NACA0004 is taken as section, can get net lift when it executes symmetrical flapping motion; with the increase of the middle wing elastic coefficient ratio, the period average lift factor increases, but the period average drag factor is not monotonous; the period average lift factor of three hinge flapping wing is obviously smaller than that of double-hinged flapping wing; with the increase of the drag wing elastic coefficient ratio, the period average lift factor and period average drag factor are still not monotonous.