Aerodynamic performance and mechanism for a flexible membrane wing encountering a harmonic transverse gust

IF 2.3 3区工程技术 Q2 ENGINEERING, MECHANICAL

Experiments in Fluids Pub Date : 2025-02-07 DOI:10.1007/s00348-025-03966-6

Xi He, Siyuan Feng, Qinfeng Guo, Jinjun Wang

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Abstract

To assess the performance of a flexible membrane wing in a harmonic transverse gust, the aerodynamic forces, membrane deformations and surrounding flow fields are synchronously measured. The gust is generated by two periodically pitching airfoils. First, the flexible wing outperforms its rigid counterparts in time-averaged lift, achieving a maximum lift increment of 44.6% at the angle of attack (α) of 16°. The lift-enhancement is attributed to the camber increase and membrane vibration to suppress flow separation—a mechanism analogous to the behavior in steady flow conditions. Second, for the unsteady lift response, the flexible and rigid cambered wings reduce lift fluctuations induced by the gust when 3° ≤ α ≤ 9°, implying a gust alleviation effect. The maximum alleviation of the flexible wing is 32.0% at α = 6°. To elucidate the gust alleviation mechanism, phase-averaged lift and flow fields at α = 6° are investigated. The flow over the flexible wing remains consistently attached, while the rigid plate wing exhibits the evolution of leading-edge vortices (LEVs). These LEVs provide additional lift that helps the rigid plate wing to match the maximum lift of the flexible wing. However, the minimum lift of the plate wing is much smaller. Consequently, the primary reason for the aerodynamic load alleviation is elaborated. However, the inherent resonant vibration of the membrane is a by-product that has a negative impact on the alleviation effect.

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来源期刊

Experiments in Fluids 工程技术-工程：机械

CiteScore

5.10

自引率

12.50%

发文量

157

审稿时长

3.8 months

期刊介绍： Experiments in Fluids examines the advancement, extension, and improvement of new techniques of flow measurement. The journal also publishes contributions that employ existing experimental techniques to gain an understanding of the underlying flow physics in the areas of turbulence, aerodynamics, hydrodynamics, convective heat transfer, combustion, turbomachinery, multi-phase flows, and chemical, biological and geological flows. In addition, readers will find papers that report on investigations combining experimental and analytical/numerical approaches.