During the past couple of months, a few colleagues have contacted me about my recent dearth of blog writing. Though trite to offer, I've been busy! Research work, teaching, and administrative duties have made little time for blog writing. What got me motivated to write a post today was an invitation from NPR to appear on All Things Considered yesterday. I was interviewed by Melissa Block about the Brazuca, which is the name of the new World Cup ball that will be employed in this summer's world tournament in Brazil. Click here to get to a page where you may listen to my four-minute interview.
In late 2013, I was invited by Takeshi Asai of the University of Tsukuba in Japan to collaborate with him on aerodynamics research of the Brazuca. Dr Asai and his colleague, Sungchan Hong, supplied me with wind-tunnel data for the Brazuca, as well as wind-tunnel data for the Jabulani, which was used in the 2010 World Cup. I spent the majority of my winter "break" analyzing data, coding trajectory models, and paper writing -- all LOTS of fun and why I LOVE my job! My colleagues and I came to the conclusion that the Brazuca is a better ball than the Jabulani. Much of the wild knuckling effects seen in 2010 should be absent this summer. The key is that despite six panels on the Brazuca compared to eight on the Jabulani, the total seam length on the Brazuca is 68% longer. That added roughness leads to a drag crisis at a smaller speed, meaning most intermediate-speed and all high-speed kicks should be in the post-critical region where the drag coefficient is essentially uniform. The Brazuca also shows better stability than the Jabulani due to more uniformity in the surface roughness. Many more details appear in our paper, which was recently published in the Journal of Sports Engineering and Technology (click here for a link to the paper).
There are only 50 more days before the 2014 World Cup commences. I'm anxious to see the new ball in action!