Effects of Geometric Parameters on Flapping Rotary Wings at Low Reynolds Numbers

Flapping rotary wing is a novel aerodynamic configuration proposed in recent years for micro air vehicles. To understand the aerodynamic characteristics of this wing layout, a computational fluid dynamics method is employed to study how certain geometric parameters of the wings, such as camber of airfoil, radius of the second area moment, twist angle, and aspect ratio, affect the flow behavior, aerodynamic forces, and moments of the flapping rotary wing at various low Reynolds numbers. Although maximum camber of airfoil affects the flow around the flapping rotary wing, it influences only the rotary moment significantly. The increase in radius of the second area moment enhances the leading edge vortex near the tip and increases the mean lift coefficient. The maximum mean rotary moment coefficient was obtained when the wing planform was close to a rectangle. The change in twist angle alters the local effective angle of attack of the wing, thereby influencing the flow and aerodynamic forces. Excessive aspect...