237 Effects of panel orientation for drag force on soccer ball

Abstract

Traditionally, the soccer balls used in soccer tournaments had 32 pentagonal and hexagonal panels. Also, 14- and 8-panel balls have been used. Recently, new 32-panel ball (Cafusa, Adidas) with unverified aerodynamic characteristics are using. There is a need to understand the aerodynamic characteristics of a new 32-panel ball that used a variety football league. The purpose of this study was to analyze the basic aerodynamic characteristics of the Cafusa ball (32-panel) by using a wind tunnel. Also, we measured the orientations (Face A, B, C) of the aerodynamic forces for Cafusa ball. The critical Reynolds number of the Face A, Face B, and Face C was 〜2.6 × 10^5 (drag coefficient, Cd ≈ 0.12), 〜2.4 × 10^5 (Cd ≈ 0.16), and 〜2.4 × 10^5 (Cd ≈ 0.15), respectively. The flight trajectory simulation suggested that Face C has less air resistance in the high-speed region than the other Faces. It is considered that the critical Reynolds number of a soccer ball depends on the panel orientations.