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Aerodynamics of a Cricket Ball

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Sanjay Mittal’s presentation begins with an intriguing comparison of how air flows around projectiles in various sports, from the spinning flight of a soccer ball to the subtle aerodynamics of a golf ball. Drawing on data from experiments conducted at IIT Kanpur’s National Wind Tunnel Facility, he takes the audience on a journey across the fields and courts of sports like baseball, cricket, tennis, volleyball, and badminton.

In professional badminton, players prefer duck-feather shuttlecocks for their unique feel and flight characteristics. However, these shuttlecocks are fragile and costly, so nylon substitutes are common in recreational play. Prof. Mittal will explore how these synthetic shuttlecocks differ aerodynamically from the traditional feathered ones, illuminating the role of fluid-structure interactions that make them fly—and feel—so differently in the air.

Cricket fans can look forward to a deep dive into the mysteries of swing and reverse swing. Can a new cricket ball actually reverse swing? Prof. Mittal answers this question by presenting results from wind-tunnel experiments and Large Eddy Simulations. He’ll explain why cricketers shine one side of the ball and how the roughness on one hemisphere affects the ball’s trajectory, enabling “contrast-swing.” With data from carefully conducted experiments on both new and worn balls, he’ll show how different surface textures create distinct swing behaviors that bowlers use to baffle batters.

Prof. Mittal then shifts focus to the “knuckleball,” which has gained attention in cricket, though he notes it’s a bit of a misnomer. Borrowing insights from baseball, he proposes a model to capture the peculiar movement of a true knuckleball, dissecting the optimal seam angle, speed, and spin rate at release that make this delivery so elusive for batters.

To wrap up, he will delve into the aerodynamics of a frisbee. With every flick and spin, the frisbee dances on a layer of air, a perfect example of how the subtle interaction of shape and flow can lead to graceful, unpredictable motion.

Prof. Mittal’s lecture will be followed by a Q&A with the audience. Mr. Srinath will offer his comments at the end.

High Tea will be served before the event from 10:30am onwards.

This lecture is a part of RRI’s Vignyana Kathegalu, a series of popular talks on science.

Presented by: Raman Research Institute, Bangalore