A computational study of the aerodynamics of plunging and pitching motions of airfoils

Abstract

Investigation of flow characteristics and force generation of flapping wings have received significant attention in modern fluid dynamics due to emerging applications like bio-inspired Micro Air Vehicles (MAVs) and energy harvesters. In this study, aerodynamic characteristics of NACA 2412 airfoil in plunging and pitching motion are simulated using an incompressible Navier Stokes solver in varying Reynolds and Strouhal numbers. The wake of the airfoil which is visualized using velocity and pressure contour plots and aerodynamic force generation are analyzed. A close agreement is obtained between numerically simulated aerodynamic characteristics including wake structure and forces in this study and experimental results in the literature. The analysis discloses that wing-wake interaction enables a dramatic increment in trust and lift forces up to 300%. Moreover, aerodynamic forces generated in combined pitching and plunging motion show a maximum of 225% increment from the numerical sum of forces in the two sub-motion in some combinations of Reynolds and Strouhal numbers, demonstrating the coupled behaviour of plunging and pitching motions.