Aerodynamic performance of the flexibility of corrugated dragonfly wings in flapping flight

摘要

At low Reynolds numbers, the variable flexibility of flapping insect wings is considered essential in improving the favorable aerodynamic forces. To further explore whether significant aerodynamic coupling exists between the microstructure and passive flexible deformation, this paper proposes three technical comparison airfoils: a corrugated wing with deformation, a symmetric flat plate wing with deformation, and a corrugated wing without deformation. Based on STAR-CCM+ software, this paper numerically solves the Navier-Stokes equations using the fluid-structure interaction method. The results show that the aerodynamic performance of the flexible corrugated wing is better than that of the rigid corrugated wing, and its lift and thrust are both improved to a certain extent, and the thrust efficiency of the flexible corrugated wing is significantly higher than that of the flexible flat plate. Although the thrust is improved, a part of the lift is lost, and as the flapping amplitude increases past 35 degrees, the disparity gradually increases. A comparison of the flexible technical airfoils shows that the corrugated structure promotes thrust and retards lift, which is closely related to the formation and dissipation of strong vortex rings during the downstroke phase. On the premise of maintaining typical flapping without falling, dragonflies can fly with skillful efficiency by adjusting the way they flap their wings. The results of this work provide new insight into the formation and role of thrust in flapping maneuvering flight and provide a specific reference for developing new bionic flapping-wing aircraft.

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