New J. Phys. (in the press)

Next time you grab a badminton racket for a casual game you might want to try some new tricks physicists have come up with. Caroline Cohen and colleagues have developed an aerodynamic model to understand the unique flight pattern of the shuttlecock and what this means for the game.

The winning advantage in badminton is in accurate control of the shuttlecock trajectory and as Cohen et al. point out, it's all about geometry. The shuttlecock can reach speeds of over 130 m s−1 and it will always hit the racket cork-first, meaning that it will always flip after impact. This is the result of an aerodynamic torque caused by the interplay between gravity and drag, which in turn occurs because of the shifted centres of mass and pressure.

Cohen and colleagues found that an opening angle of around 45 degrees minimizes the flipping time. The shuttlecock rotates around its axis because of the asymmetry of its skirt and the choice of material turns out to be quite important. Feather skirts have a slightly larger drag than plastic ones, but also higher rotation speeds — both very important in controlling the trajectory.