It’s that time again, when the world’s most beloved sport pits one country against another. Soccer, or football as the rest of the world calls it, draws the attention of hundreds of millions of fans especially during the World Cup. There are heated and sometimes violent disagreements as to who’s team is the greatest of all time, what referee makes the worst call and who is obviously cheating. Sometimes, even the ball itself is to blame for intense contention between fans. With this in mind, after the last World Cup frustration when their Jabulani soccer ball behaved erratically at times, Adidas worked with a number of players in the design and construction of this year’s regulation soccer ball, the Brazuca.
NASA also has football fever, they set up the traditional 32 panel soccer ball and the new Brazuca ball in their 2 foot by 2 foot wind tunnel at the Ames’ Fluid Mechanics Laboratory to see how air flows around the different designs. To the untrained eye, such as mine, one might think that a soccer ball is just as good as the next. The kind we used as children had the iconic 32 diamond panels and were relatively smooth. It would be easy to think that a spherical object with a smooth surface would be the most aerodynamic, well you would be wrong. The smooth sphere creates a large amount of drag behind a soccer ball, since all of the air is flowing around it and meeting at the tail end to create an area of low pressure behind.
The Jabulani ball had eight panels and was relatively smooth. The Brazuca only has six panels, with longer, deeper seams and a surface that is covered with small bumps. The bumps disturb the air around the ball, decreasing drag and the size of the low pressure wake behind it. This causes the soccer ball to travel further.
So what will be different this year then 4 years ago? The Brazuca ball should travel more predictably, instead of knuckling off in a random directions. While kickers may be bummed, the goalies will surely appreciate a more stable flight pattern.