柔性扑翼的气动特性研究

以往扑翼的气动力计算研究都很少考虑扑翼的柔性,而在鸟的扑翼动作中,在外加气动力和鸟自身的扑动力作用下,扑翼的柔性变形相当大。本文在原有匀速刚性模型的基础上,提出考虑了扑翼扑动速率变化和形状变化的扑翼分析模型,使之更接近鸟翼柔性扑动真实情况。通过计算分析气动特性发现,控制适当的话,柔性变形能大大改善扑翼的气动性能。本文通过模拟鸟扑翼的柔性运动,计算了时柔性扑翼气动力以及平均升力系数和平均推力系数随着扑动角、倾斜角等参数变化的情况,从而从气动的角度解释了为什么鸟在不同的飞行阶段扑翼规律各不相同,并为柔性扑翼飞行器的设计提供了理论依据。

Aerodynamic Computation of Flexible Flapping-Wing

In the past researches of flapping wing, the flexibility of wing was ignored, but when a bird flies, the wings are deformed seriously mder the outer aerodynamic loads and the inner forces. On the base of the conventional rigid wing flap model, a new flexible flapping wing flap model considering the change of flap velocity and the deformation of wing was developed to approach to the real flap motion of bird wings. Comparied the aerodynamic loads of rigid wing with flexible wing, it is found that a proper deformation enubles to enlarge the lift and thrust of flapping wing. In addition, the flexible flapping wing's lift coefficient and thrust coefficient changed with flap model parameters such as flap angel and incline angel, are evaluated. The computed results explain why bird flap wing follows the different rules in the individual flying phases, and provide reference data for future design of ornithopter with flexible flapping wing.