Numerical Investigation on Aerodynamic Characteristics of Damaged Infinite Wings With Variation in Penetration Angle

Abstract

Aerodynamic performance of a full span NACA 641-412 airfoil with a circular-shaped damage at various attack directions has been numerically investigated in this study. To assess the aerodynamic effects of different penetration angles in which threats such as projectiles can pass through the wings, attack directions of 30°, 60°, –30° and –60° relative to the normal axis of the chord line has been studied and compared with attack direction of 0°. To validate with published studies about damaged wing, the 200 mm chord airfoil was simulated with the damage hole diameter of 20% chord at the midspan and midchord location in Reynolds number of 500,000. Quantitative and qualitative results of this numerical study had a good agreement with published experimental data due to appropriate structured mesh and turbulence modelling. In addition to lift, drag and pitching moment coefficient, surface pressure distribution around the damage hole has been studied. Results show that, if the penetration angle becomes more negative, aerodynamics performance of the wing will be further decreased; therefore, attack directions of threat mechanisms such as “ahead and above” or “below from the rear” have severe negative impact than other directions on aerodynamic performance of the damaged infinite wing.