Fig. 5. Rotational motion (t) of two wings during fling and the corresponding lift forces. (A) The broken line represents the motion used in the clap and fling experiments of Spedding and Maxworthy (1986). The solid line represents the rotational motion of the wings used in the immersed boundary simulation. The motion used by Sun and Yu (2003) is nearly identical. (B) The dotted line represents the lift forces measured over time in Spedding and Maxworthy's experiment at a Reynolds number (Re) of about 3 x10³. The solid line represents the lift forces calculated by Sun and Yu at the same Re. The broken line represents the scaled lift forces calculated over time in the immersed boundary simulation at Re=128.