Numerical Investigation on the Aerodynamic Performance of NACA Series Airfoils at Low Reynolds Numbers

Abstract

In this paper, aerodynamic performance of three NACA airfoils, including NACA 2412, NACA 4412, and NACA 0012 are examined in two-dimensional CFD simulation to compare their aerodynamic performance. The current simulation is conducted at Re = 1.0 × 10 5 with turbulence model is able to predict adverse pressure gradient. The flow field is examined in a range of angle of attack between 0 and 16 degrees. Numerical results reveal that when Re is low, increasing camber not only increases both baseline lift and maximum lift coefficient, but also delay the stall. The symmetric airfoil NACA 0012 stalls at about 8°, while more cambered airfoil NACA 4412 delay stall at about 14°, obtain higher lift-to-drag ratio at peak and wider efficient operating range. The surface pressure, velocity and turbulent kinetic energy are further analyzed. It is found that when camber is increased, the adverse pressure gradient on upper surface is improved and transition point moves backward with angle of attack, which can suppress the large scale separation and vortex evolution.