The technical evolution of the soccer ball: Using wind-tunnel experiments to compare the World Cup 2014 ball with the one used in 2010

A comparison of Jabulani and Brazuca non-spin aerodynamics

From Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology                                                         

Much of the world is riveted by the (FIFA) World Cup action, which takes place every 4 years. Soccer, perhaps more than any other sport due to its global popularity, has been studied extensively by scientists and engineers for a few decades now. Some of that soccer work, like the work discussed in this article, seeks to understand how the technical evolution of the soccer ball affects play at the highest level. Since 1970, Adidas has provided the ball used at the World Cup. The ball itself has changed over the years. Jabulani was the name of the ball created for the 2010 World Cup in South Africa, a ball that experienced some controversy. For the 2014 World Cup in Brazil, Adidas has created the Brazuca ball.

This article compares the 2010 Jabulani World Cup ball and the Brazuca ball currently used in the 2014 World Cup.  The paper reports the results of wind-tunnel experiments on these balls. Wind-tunnel results are used to create model trajectories that will show how differences in aerodynamic properties lead to differences in flight trajectories. Because of the ball’s reduced critical speed, goalkeepers are likely to note a significant reduction in erratic ball trajectories in the 2014 World Cup compared to the 2010 World Cup.

Abstract

Wind-tunnel experimental measurements of drag coefficients for non-spinning Jabulani and Brazuca balls are presented. The Brazuca ball’s critical drag speed is lower than that of the Jabulani ball, and the Brazuca ball’s super-critical drag coefficient is larger than that of the Jabulani ball. Compared to the Jabulani ball, the Brazuca ball suffers less instability due to knuckle-ball effects. Using drag data, numerically determined ball trajectories are created, and it is postulated that although power shots are too similar to note flight differences, goalkeepers are likely to note the differences between Jabulani and Brazuca ball trajectories for intermediate-speed ranges. This latter result may appear in the 2014 World Cup for goalkeepers used to the flight of the ball used in the 2010 World Cup.

 

Read this article for free

Article details
John Eric Goff, Takeshi Asai, and Sungchan Hong
A comparison of Jabulani and Brazuca non-spin aerodynamics
Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology 1754337114526173, first published on March 18, 2014 doi:10.1177/1754337114526173

 

 

 

 

 

     
This entry was posted in Engineering, SAGE Insight, Technology and tagged , , , , , , , , . Bookmark the permalink.