Cal Tech Scientists Put World Cup Ball to the Test
By Terry Miller
Published: Monday, June 28th, 2010
Caltech Scientists Test Air Flow Over the 2010 World Cup Soccer Ball
One of the main differences among soccer balls is how much the air flow follows the ball’s surface. Turbulent air flow would hug the curvature of the ball, reducing drag. In this high-speed video of the Jabulani ball, however, Caltech scientists demonstrate that the air flow actually separates after about halfway across the ball.
The World Cup is in full swing, complete with an official new soccer ball named Jabulani, meaning “to celebrate” in Zulu. The players, however, aren’t exactly celebrating. Instead, many of them are complaining that the ball’s trajectory is too hard to predict, and that the ball itself is too hard to control, resulting in wayward passes, shots flying off target, and goalkeepers looking silly. So what exactly is it about the new ball that’s provoking all the controversy? To find out, Caltech engineers in the lab of Assistant Professor of Aeronautics Beverley McKeon put an official Jabulani through its paces in the Lucas Adaptive Wall Wind Tunnel. And what they found there may explain the seemingly unpredictable nature of the Jabulani.