The effect of atmospheric conditions on the swing of a cricket ball

The aerodynamic mechanisms that produce swing, and reverse swing in cricket are well understood and the phenomenon has often been measured in wind tunnel tests. However, it is widely believed throughout the cricketing community that atmosphericconditions can have a dramatic effect on a bowler's ability to make the ballswing, and this has perplexed the minds of sports engineers for decades. A sophisticated trajectory model was developed to investigate how different atmosphericconditions affect the swing of acricketball, and similar to previous studies, humidity was found to have no effect. Previous studies have suggested that certain atmosphericconditions may actually change the geometry of the cricketball thereby exaggerating the asymmetric air flow around its body and thus increase the swing force. This hypothesis was tested by conditioning cricketballs inside an atmospheric chamber and then accurately measuring their geometry with a 3D laser scanner. The mass of the balls were also measured through the range of atmosphericconditions. It was found that the mass of aball can change in different playing conditions, but no atmosphericconditions could cause a significant change to the ball geometry. It was concluded that if there is a real effect of atmosphericconditions on cricketballswing it must be caused by an entirely different mechanism. It is proposed that new avenues for investigation should focus on how differing levels of cloud cover may affect localized air turbulence.