Influence of corrugation position on aerodynamic performance of dragonfly gliding airfoils

The aerodynamic performance of airfoil can be optimized by changing the corrugation structure of insect wings, which can benefit the aerodynamic design of micro air vehicles. The gliding aerodynamic performances of three dragonfly-mimic airfoils, with corrugation located at the leading edge, trailing edge and middle position, were studied respectively by using computational fluid dynamics (CFD) method. The gliding angle of attack rose from 0° to 20°, and Reynolds number ranged from 700 to 2300. The results showed that the airfoil with the corrugation located at the trailing edge had the largest lift coefficient and lift-drag ratio at different angles of attack and Reynolds numbers, presenting the best gliding aerodynamic performance; when gliding at the angle of attack of 10° at Reynolds number of 1500, the time-averaged lift coefficient of the airfoil with the corrugation at the trailing edge was 58% and 82% larger than that of the airfoil with the corrugation at the leading edge and middle position, and the lift-drag ratio increased by 49% and 33%, respectively; the vortices in the corrugated trailing edge made the leading edge vortex more concentrated and closer to the wing surface, and delayed the shedding of the leading edge vortex.