Three-dimensional CFD model and aerodynamic analysis of dragonfly’s corrugated wing during gliding

The aerodynamic performance of micro air vehicles (MAVs) in low-speed flight would be improved by mimicking the dragonfly’s wing with corrugated airfoil. Research on two-dimensional corrugated airfoils has revealed that the local vortex in the corrugated structure increases the flow speed and the lift-to-drag ratio in low Reynolds numbers. However, studies seldom focus on the effects of three-dimensional corrugated structures on aerodynamics. In this paper, the mechanism of high aerodynamic performance in a dragonfly’s wing is studied considering a three-dimensional corrugated structure. The high-fidelity dragonfly forewing model is established through reverse engineering. The computational fluid dynamics (CFD) simulation is performed for the gliding corrugated wing with angles of attack (AOA) of 0°~24° under three Reynolds numbers. The flow characteristics of corrugated wings and the aerodynamic gain from it are analyzed through the simulated streamlines and pressure contours, as well as the comparison between the corrugated wing, flat wing, and flat plate. The results show that the aerodynamic characteristics of corrugated wings are generally superior. Although the introduction of the corrugated structure increases some drag, it brings a higher lift and lift-to-drag ratio than the flat wings.