Department of Aerospace Engineering, College of Aeronautical Engineering, National University of Sciences and Technology, Islamabad, Pakistan.
Bioinspir Biomim. 2021 Oct 25;16(6). doi: 10.1088/1748-3190/ac28eb.
Flapping wing micro aerial vehicles are studied as the substitute for fixed and rotary wing micro aerial vehicles because of the advantages such as agility, maneuverability, and employability in confined environments. Hummingbird's sustainable hovering capability inspires many researchers to develop micro aerial vehicles with similar dynamics. In this research, a wing of a ruby-throated hummingbird is modeled as an insect wing using membrane and stiffeners. The effect of flexibility on the aerodynamic performance of a wing in hovering flight has been studied numerically by using a fluid-structure interaction scheme at a Reynolds number of 3000. Different wings have been developed by using different positions and thicknesses of the stiffeners. The chordwise and spanwise flexural stiffnesses of all the wings modeled in this work are comparable to insects of similar span and chord length. When the position of the stiffener is varied, the best-performing wing has an average lift coefficient of 0.51. Subsequently, the average lift coefficient is increased to 0.56 when the appropriate thickness of the stiffeners is chosen. The best flexible wing outperforms its rigid counterpart and produces lift and power economy comparable to a real hummingbird's wing. That is, the average lift coefficient and power economy of 0.56 and 0.88 for the best flexible wing as compared to 0.61 and 1.07 for the hummingbird's wing. It can be concluded that a simple manufacturable flexible wing design based on appropriate positioning and thickness of stiffeners can serve as a potential candidate for bio-inspired flapping-wing micro aerial vehicles.
扑翼微型飞行器因其灵活性、机动性和在受限环境中的适用性等优点，被研究作为固定翼和旋转翼微型飞行器的替代品。蜂鸟的可持续悬停能力激发了许多研究人员开发具有类似动力学的微型飞行器。在这项研究中，使用膜片和加强筋将蜂鸟的翅膀建模为昆虫翅膀。通过在雷诺数为 3000 的情况下使用流固耦合方案，数值研究了在悬停飞行中柔性对机翼空气动力性能的影响。通过使用不同位置和厚度的加强筋开发了不同的机翼。本工作中建模的所有机翼的弦向和展向弯曲刚度与类似弦长和展长的昆虫相当。当加强筋的位置发生变化时，性能最佳的机翼的平均升力系数为 0.51。随后，当选择合适的加强筋厚度时，平均升力系数增加到 0.56。最佳柔性机翼的性能优于其刚性对应物，并产生与真实蜂鸟翅膀相当的升力和功率效率。即，最佳柔性机翼的平均升力系数和功率效率为 0.56 和 0.88，而蜂鸟翅膀的平均升力系数和功率效率为 0.61 和 1.07。可以得出结论，基于适当的加强筋定位和厚度的简单可制造柔性机翼设计可以作为仿生扑翼微型飞行器的潜在候选方案。
