The purpose of this paper is to achieve an optimum flow separation control over the airfoil using passive flow control method by introducing bio-inspired nose near the leading edge of the NACA 2412 airfoil.Design/methodology/approachTwo distinguished methods have been implemented on the leading edge of the airfoil: forward facing step, which induces multiple accelerations at low angle of attack, and cavity/backward facing step, which creates recirculating region (axial vortices) at high angle of attack.FindingsThe porpoise airfoil (optimum bio-inspired nose airfoil) delays the flow separation and improves the aerodynamic efficiency by increasing the lift and decreasing the parasitic drag. The maximum increase in aerodynamic efficiency is 22.4 per cent, with an average increase of 8.6 per cent at all angles of attack.Research limitations/implicationsThe computational analysis has been done for NACA 2412 airfoil at low subsonic speed.Practical implicationsThis design improves the aerodynamic performance and increases structural strength of the aircraft wing compared to other conventional high-lift devices and flow-control devices.Originality/valueDifferent bio-inspired nose designs which are inspired by the cetacean species have been analysed for NACA 2412 airfoil, and optimum nose design (porpoise airfoil) has been found.
Aircraft Engineering and Aerospace Technology – Emerald Publishing
Published: Aug 15, 2019
Keywords: Airfoil profile modification; Axial vortex generation; Flow separation control; Bio-inspired nose airfoil; Passive flow separation control; NACA 2412