This is seriously off-topic but, as the Copa
America and Euro have been transfixing millions in front of their TV’s
this timely research may be of interest. Previously we’ve heard
‘scientific’ analyses of how and why a football’s trajectory bends in
flight which, err, fly in the face of reality. A new computational
fluid dynamics model developed by Mentor Graphic’s Sergio Antioquia
explains in detail, with embedded graphics, the physical
phenomena that make the ball swing.
Besides gravity, three different aerodynamic forces act on a moving ball, drag, magnus and wobble. You will have to read the paper to find out what these mean but they combine in various measures to produce both the erratic (and unsatisfactory) trajectory of a beach ball and the elegant curveball of the well struck free kick that just dips under the bar.
Antioquia produces streamlines and velocity contours from Mentor’s FloEFD application to illustrate the different effects and backs these up with real world YouTube videos of great goals of history. Ronaldo’s folha seca strike that leaves the goalie smiling in admiration from a seated position is worth a look. Download the gem of a paper from Mentor (registration required).