Test The Limits

Super Bowl 50: unrealized aero potential

By Exa

February 10 2016

In what will probably turn out to be the final game for the first quarter back in NFL history to reach an incredible 200 career wins, Peyton Manning’s Denver Broncos put on a defensive masterclass to seize Super Bowl 50.

 

Just under half of all Americans with a TV set tuned in for the half-century anniversary of the American classic event, which over the decades has produced pinpoint throwing, exhilarating runs and acrobatic receptions. This wasn’t one of those years.

 

Instead, what the viewing public was treated to was a very carefully orchestrated defensive display from Denver, headed up by MVP linebacker Von Miller. That said, we wanted to shed some light on the aerodynamic performance of the game football, on the rare occasions that it was let loose and properly allowed to fly.

 

For an 11-inch football weighing in at approximately 0.41 kg and traveling at an example speed of 55mph through the air, we discovered that a 10° angle of attack allows for the perfect throw. To stabilize its flight under these conditions, the quarterback would need to produce a ball rotation of up to 600rpm for optimum speed and accuracy.

 

Interestingly though, what might appear to be a perfectly stable and equal flight path through the air, often actually isn’t. The force generated by the rotation is affected by the shape of the ball itself, leading to a slight wobble, even when perfectly thrown.

 

This behavior is further emphasized by the raised stitching on the sides of the ball, producing an adverse effect on its momentum as it travels through the air. The position of the pronounced stitching increases aero separation, resulting in a continuous imbalance and resultant wobble (Peyton had a few of those), which deviates by one full revolution off center, every time the ball rotates six times on its axis.

 

If the designers of the football utilized a spiraled or angled seam to re-enforce the rotation of the football as it flies this might allowing longer and more accurate throwing capability.

 

In a game of few clear-cut chances, perhaps a CFD optimized ball wouldn’t have been a bad idea after all – but just as North Carolina will be feeling – there’s always next year, right?