Aerodynamic Characteristics of New Volleyball for the 2020 Tokyo Olympics

• Main Authors: Sungchan Hong, Hiroki Ozaki, Keita Watanabe, Takeshi Asai
• Format: Article
• Language: English
• Published: MDPI AG 2020-05-01
• Series: Applied Sciences
• Subjects: aerodynamics; Tokyo Olympics; volleyball
• Online Access: https://www.mdpi.com/2076-3417/10/9/3256

The pattern of a modern volleyball is greatly different from that of a conventional volleyball, with several changes being made to the shape and design of the surface on the ball. Furthermore, at the 2020 Tokyo Olympics, a new volleyball (V200W; Mikasa) with 18 panels will be shown as the official ball. Therefore, this study compared the basic aerodynamic characteristics of conventional volleyballs with those of new designs in a wind tunnel. We used three full-size FIVB (Fédération Internationale de Volley-Ball) official volleyballs (V5M5000; Molten, MVA200; Mikasa and V200W; Mikasa) to determine the aerodynamic forces acting on each ball. The results indicate that the critical Reynolds number (<i>Re</i>_cr) differed depending on the ball types and their orientations. The <i>Re</i>_cr for the Molten ball (conventional) was determined to be ~3.4 × 10⁵ (<i>Cd</i> = 0.17) on panel orientation A and ∼2.7 × 10⁵ (<i>Cd</i> = 0.14) on panel orientation B. Moreover, the <i>Re</i>_cr for the conventional Mikasa ball was determined to be ~2.6 × 10⁵ (<i>Cd</i> = 0.14) on panel orientation A and ∼3.0 × 10⁵ (<i>Cd</i> = 0.13) on panel orientation B. On the other hand, the critical Reynolds number for the new volleyball (V200W) was ∼2.9 × 10⁵ (<i>Cd</i> = 0.17) in the panel orientation A and ∼2.6 × 10⁵ (<i>Cd</i> = 0.15) in panel orientation B. From these results, it can be hypothesized that, during a float serve, the flight trajectory will change depending on the type of volleyball and their orientation.