Experimental Study on Effect of Wavelength and Amplitude of Wavy Ground on a NACA 0012 Airfoil

The effect of wavelength and amplitude of a sinusoidal wavy ground on the aerodynamics and flowfield of a NACA 0012 airfoil at low Reynolds numbers was investigated experimentally. The results show that, regardless of wave length and amplitude, the periodic variation in the sectional lift and pitching moment persisted, and that the smaller wavy ground distance the larger lift and pitching moment became. The pitching moment also had an opposite trend to the lift. The maximum and minimum lift always occurred at wave peak and valley, respectively. The maximum and minimum lift and pitching moment increased drastically with increasing wave amplitude while depended weakly on the wave length. However, the change in the drag force over the wavy ground was found to be nonmonotonic.