Fig. 8. A computational fluid dynamic study of unsteady aerodynamics of a two-dimensional (2-D) model of the right forewing in forward flight. (A) A systematic diagram of the 2-D computational model. The geometric model is a flat-plate airfoil with the same length as the mid-span chord length and a thickness approximately 2% of the chord length. The angle of stroke plane is defined as the included angle of the stroke plane and the plane X'O'Z' plane of the body-centered coordinate system. The kinematic model consists of a translational motion and a rotational motion. (B) Plots of time-varying force coefficients in a complete beating cycle with and without camber deformation. The force coefficients C_y and C_z represent the time-variations of drag and lift, respectively. LPCD, large positive camber deformation; NCD, negative camber deformation. (C,D) Flow patterns at zero flapping angle during downstroke with (C) and without (D) camber deformation. Velocity vectors and pressure contours are drawn to visualize the flow patterns about the airfoil; and blue in the color map denotes low pressure and red is high pressure.

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