Study of motion pattern effects on pitching flapping-foil hydrodynamic

Flapping foil propulsion with high-efficiency, maneuvering capability becomes a hot topic recently. However, most research about flapping-foil motion patterns focused on pure sinusoidal pattern. Effect of flapping-foil motion pattern to the hydrodynamic performance was presented in this paper by numerical simulations of 2D flow around a NACA0012 foil with asymmetric and non-sinusoidal pitching motion. The simulation result shows that asymmetry motion can significantly improve instantaneous thrust and lift of flapping-foil, thrust could be increased up to 50 percent when the asymmetry difference between up-ward and down-ward flapping procedure up to 0.2 cycle; Compared to the pure sinusoidal motion, the non-sinusoidal motion could increase thrust by 25 percent and efficiency by 60 percent.