A study of baseball and softball aerodynamics

Abstract

Baseball and softball are popular sports in many parts of the world especially in North America. These games are enjoyed both by participants and spectators. The flight trajectory of a baseball and softball largely depends on their aerodynamic characteristics. Despite the popularity of the game, it appears that little information on the aerodynamic force experienced by a baseball and softball is available. Having curved stitches, complex seams and their orientation, the airflow around these balls are believed to be significantly complex and little understood. The primary objective of this study was to measure aerodynamic drag of a series of baseballs and softballs. The aerodynamic forces and moments were measured experimentally for a range of wind speeds and seam orientations. The aerodynamic forces and their non-dimensional coefficients were analysed. The results indicate that the drag coefficients of a baseball and softball did not undergo a distinctive drag crisis as a smooth sphere due to their complex seams and their orientation. The findings also indicate that the seam orientation had profound impact on aerodynamic characteristics of both balls.