In this paper, we consider the effect of different flapping kinematics on the generation of aerodynamic forces in a pair of wings in forward flight. To this end, we use an unsteady panel method solver to perform a parametric study of three different parameters: the flapping radius, the reduced frequency, and the aspect ratio. Varying the flapping radius the motion of the wings smoothly changes from pure flapping (R = 0, rotation around the wing root) to heaving (R = ∞, vertical oscillation of the wings). The results indicate that the thrust generated increases with the flapping radius and the reduced frequency. However, the propulsive efficiency changes little with the radius of flapping (less than 2%), and remains roughly constant for R (≥) 2c. Only for small aspect ratios (AR = 1) the results show a slightly better propulsive efficiency for flapping with R ≈ 3c over heaving.
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