An Experimental Investigation on a Bio-inspired Corrugated Airfoil

An experimental study was conducted to investigate the aerodynamic characteristics of a bio-inspired corrugated airfoil compared with a streamlined airfoil and a flat plate at the chord Reynolds number of Re= 58,000 ~ 125,000 to explore the potential applications of such bio-inspired corrugated airfoils for micro air vehicle (MAV) designs. In addition to measuring the aerodynamic lift and drag forces acting on the tested airfoils, a digital particle image velocimetry system was used to conduct detailed flowfield measurements to quantify the transient behavior of vortex and turbulent flow structures around the airfoils. The measurement result revealed clearly that the corrugated airfoil has better performance over the streamlined airfoil and the flat plate in providing higher lift and preventing large-scale flow separation and airfoil stall at low Reynolds numbers. The detailed flow field measurements were correlated with the aerodynamic force measurement data to elucidate underlying physics to improve our understanding about how and why the corrugation feature found in the dragonfly wings holds aerodynamic advantages for low Reynolds number flight applications.