Numerical investigations into the nonsinusoidal motion effects on aerodynamics of a pitching airfoil

The growing applications of wind turbine impose the need for accurate flow solutions of airfoils with different pitching motions. In this paper an adjustable parameter K is employed to realize various nonsinusoidal motions and the effects of nonsinusoidal motion on pitching airfoil aerodynamics of a 2-D NACA0012 airfoil are numerically studied at Re=1.35×10^;5;. The nonsinusoidal motion effects on the instantaneous force coefficients and flow patterns are studied at different unsteady parameters (amplitude of oscillation, θ reduced frequency, k). The results reveal that the nonsinusoidal motion noticeably affects the instantaneous force coefficients, maximum lift and drag coefficients. Besides, the formation of leading edge vortices and flow structures are also affected by the nonsinusoidal motion.