Scientists raise concerns over the FIFA World Cup ball

"In plain language, that suggests a hard-hit long ball may lose a little range. 'In our simulations, the difference is not huge. But it is large enough that players may notice long kicks coming up a few meters short.'"

"To make up for the short seam length, which would make the ball smoother, Adidas included deep grooves on each panel and added a rough outer texture. Dr John Eric Goff, a physicist at the University of Puget Sound, says that this has created changes to the 'drag crisis' which could cause problems for powerful kickers."

"Dr Goff and his co-authors placed the new Trionda ball in a wind chamber to measure something called the drag coefficient. This is a way of describing how air moves around the ball and how much drag the ball experiences in flight. They then put these measurements into a computer simulation to show how it would perform in a real-life game."

"The critical detail which separates a good, consistent ball from an unpredictable one is something called the drag crisis. As the ball flies, a thin layer of air gets trapped next to the surface, reducing the overall drag and helping it fly further. But once the ball hits a certain speed, this layer starts to become tu"

The Trionda World Cup ball uses a four-panel design and a smooth profile that initially raised concerns about unpredictable flight similar to the 2010 Jabulani. Adidas added deep grooves and a rough outer texture to compensate for a shorter seam length that would otherwise make the ball smoother. Researchers measured the ball’s drag coefficient in a wind chamber and used those results in computer simulations to estimate real-game performance. The key factor is the drag crisis, where a thin air layer near the surface reduces drag until a critical speed is reached. The Trionda’s design changes the drag crisis behavior, which could cause powerful long kicks to lose some range. Simulations suggest the effect is not huge but may be noticeable.

Read at Mail Online