Influence of Surface Properties on Soccer Ball Trajectories

John Eric Goff,Takeshi Asai,Sungchan Hong

doi:10.3390/proceedings2020049143

Abstract

In this paper, we summarize our recent research work on soccer balls. Employing wind tunnels and analyses of simulated trajectories, we have gained an understanding of how various surface features influence soccer ball aerodynamics. Wind tunnels provide aerodynamic coefficients for non-spinning soccer balls. The coefficients then help determine the trajectories of various simulated kicked balls. Surface features include panel texturing, seam width, and seam depth. We have determined that small changes in surface texturing can lead to hard-kicked soccer balls experiencing lateral deflections as large as 10%–20% of their horizontal ranges. We have also found that the critical Reynolds number for soccer balls is more strongly correlated with seam width than with seam depth.

Highlights

Sports such as baseball, basketball, and American football employ balls whose designs are rigidly specified by their respective governing bodies
Besides gaining a fundamental understanding of how air flow interacts with a surface, such as on a soccer ball, understanding how a soccer ball’s surface features, like seams, panel shapes, panel texturing, and total seam length, influence a ball’s trajectory is crucial if ball manufacturers are to produce new balls that have very similar aerodynamic properties to the balls players are accustomed to using
The focus of the following meta-analysis will be on the critical Reynolds number and how the various surface features of a soccer ball influence that number

Summary

Introduction

Basketball, and American football employ balls whose designs are rigidly specified by their respective governing bodies. If one wishes to fundamentally understand how air acts on a soccer ball, and if one wishes to model the flight of a soccer ball through air, one must find the drag, side, and lift coefficients as functions of the center-of-mass translational speed and the angular speed about the center of mass. Those coefficients depend on the surface features of a soccer ball, such as the panel geometry, panel texturing (if any), and seam geometry. The authors of this work have used a wind tunnel as the primary tool for finding the aerodynamic coefficients

Experimental Methods and Discussion

Meta-Analysis

Surface Influences on Ball Trajectory

Findings

Conclusions