Computational study on effect of free-stream turbulence on bio-inspired corrugated airfoil at different sections at low Reynolds number

During flight, dragonfly wings can be thought of as an extreme light-weight airfoil. Many of the flight properties of tiny dragonfly wings are also shared by micro aerial vehicles (MAVs), which are nowadays finding widespread use in military and other commercial applications. It is observed that dragonflies have distinct cross-sectional corrugation that function to produce different local-aerodynamic characteristics. Along the wing’s longitudinal axis, there are significant variations in corrugation profile which adapts to different flight condition accordingly. Dragonflies fly in the extremely low-Reynolds-number zone, showcasing their outstanding flying characteristics even in turbulent conditions. The current study focuses on understanding the effect of free-stream turbulence on three distinct 2D corrugation profile located at 0.3, 0.5, 0.7 relative to wing span length during dragonfly’s gliding phase. The corrugation pattern required for computational analysis was designed in CATIA and imported to the commercially available CFD software ANSYS. The computational study is conducted on 2D, static non-flapping three corrugated profile at 10,000 Reynolds number subject to turbulence intensity of 0.5%, 1–10% at various angle of attack. This study examines the aerodynamic performance of each corrugation profile. The current numerical analysis shows that at a positive angle of attack, the increase in the lift coefficient remains largely unaffected by the corrugated pattern on the wing’s suction area. Virtual airfoils are created by rotating vortices that are trapped in profile valleys of corrugation patterns.