サッカーボールパネルによる空力特性の違いとその原因

抄録

The design of the soccer balls continues changing almost every world cups. The difference in panel shape gives a major influence on the aerodynamic characteristics that affect ball trajectory. The purpose of this research is to investigate the aerodynamic characteristics of these balls, to propose a predisposing factor for designing a ball with high controllability. Regarding 11 kinds of soccer balls, the measurement of the fluid force and panel groove as panel shape measurement were performed. The difference in flow separation position were confirmed by an oil film method and compared with the drag coefficient of each ball. The landing position was also measured using a roller type ball launcher in the same spin rate launcher in the same spin rate launch speed and launch angle constant. As a result, it was found that the rapid change of drag characteristics in the Reynolds number differs depending on the shape of the panel groove and the panel shape that also relates to the controllability of the ball. This is found to be related to the turbulent transition position on the ball surface. To design a soccer ball, it was found to be important to consider the total groove volume of the ball.