Fluid mechanics of flapping wings
Fluid mechanics of flapping wings
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DOI：
10.1016/j.expthermflusci.2008.05.003
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发表时间：
2008-09-01
影响因子：
3.2
通讯作者：
Soria, J.
中科院分区：
文献类型：
--
作者：
von Ellenrieder, K. D.;Parker, K.;Soria, J.
在二维扑翼研究的基础上，探讨了定常巡航时Strouhal数的选取。提出了自然扑翼推进中的Strouhal数选择是一个极限环过程的假设，并探讨了这一假设对自由飞行系统的设计、控制和计算/实验建模的意义。建议使用扑翼推进的人造系统的稳态推进效率必须设计在内部，而不是主动控制，感官反馈可能对机动/加速过程中的控制更重要，对飞行/游泳系统的稳定向前运动的调节作用较小。并对三维平动和旋转翼的绕流结构进行了简要的文献综述。在平移翼的情况下，流动结构由一串相互连接的涡环组成，并且具有很强的Strouhal数依赖性。对于旋转翼，前缘涡对升力和推力的发展尤为重要。这种前缘涡旋的稳定性很大程度上依赖于跨距流动的发展，这种流动在机翼前缘产生的涡量和向尾流输送涡量之间创造了平衡。(C)2008 Elsevier Inc.保留所有权利。
Based on the results of two-dimensional flapping wing studies, the selection of Strouhal number for steady cruising is explored. The hypothesis that Strouhal number selection in natural flapping wing propulsion is a limit cycle process is proposed and the implications of this hypothesis for the design, control and computational/experimental modeling of freely flying systems are explored. It is suggested that the steady-state propulsive efficiency of man-made systems that use flapping propulsion must be designed-in, rather than actively controlled and that sensory feedback may be more important for control during maneuvering/acceleration and play only a minor role in the regulation of a flying/swimming system's steady forward motion. A brief literature review of the structure of the flow around three-dimensional translating and revolving wings is also presented. In the case of translating wings the flow structure consists of a chain of interconnected vortex loops and has a strong Strouhal number dependence. For revolving wings the leading edge vortex is especially important for the development of lift and thrust. The stability of this leading edge vortex is strongly dependent on the development of a span-wise flow that creates a balance between the creation of vorticity at the leading edge of the wing and the transport of vorticity into the wake. (C) 2008 Elsevier Inc. All rights reserved.