Development for Low Resistance Sport-Goods Considering Surface Form

Abstract

The pattern of the official ball used in the 2006 FIFA World Cup is considerably different from that of a conventional soccer ball （having 32 pentagonal and hexagonal panels）. Depending on the number of different panels and their orientation, the aerodynamic force experienced by a ball is believed to change, which in turn changes the ball trajectory. However, not much is known about the impact of the surface forms of a ball on its aerodynamics. Therefore, in the present study, 5 different types of soccer balls were produced and their aerodynamic properties were studied by wind tunnel experiments. The results confirmed that the aerodynamic force acting on the ball varied considerably depending on the surface form of the balls. Thus, the fact that the aerodynamic force acting on the ball varies depending on the surface form of the soccer ball suggests that surface roughness is also one of the important factors that determine the aerodynamic characteristics of the ball in addition to the shape and number of panels.