Abstract
Aerodynamic characteristics of badminton shuttlecocks were investigated in a vertical wind tunnel. The drag coefficients were roughly 0.8 in the free flight condition having a self-rotation, whose spin rate amounted to roughly 0.25. On the other hands, in the condition of no rotation, which have been artificially realized, the drag coefficients were of the order of roughly unity. The results suggest a great effect of the self-rotation on shuttlecock performances. Observations by tufts and smokes made clear flow patterns around the shuttlecocks and the differences in the flow fields between both conditions with and without self-rotation.