Fig. 2. Computational and experimental lift and drag coefficients during advanced rotation (=/4; A₀/c=2.8). (A) Lift (C_L) and drag (C_D) during the first four complete strokes. Red, experimental measurements; blue, computations. The time is normalized with the flapping period. The force is normalized by the maxima of the corresponding quasi-steady forces. (B) Experimental and (C) computational force vectors superimposed on wing positions, plotted at equal time intervals. The green line represents the wing chord; filled circles, the leading edge; arrows indicate force vectors on the wing. R, right; L, left.