バレーボールの空力係数に及ぼす表面形状の影響

抄録

Volleyball is a sport that begins with the serve, so effective service is essential to winning matches. The trajectory of the ball changes in a complex manner under the influence of fluid forces that depend on the speed, number of revolutions, and shape of the frame. Therefore, the purpose of this study was to understand the aerodynamic characteristics of the ball and to propose an ideal serving method by measuring fluid forces, measuring flight trajectory, and analyzing particle image velocimetry. In wind tunnel experiments, the fluid forces on the ball were measured at wind speeds ranging from 4 to 28 m/s. The results showed that the fluid force on the ball strongly depends on the type of ball and the orientation of the panel. In the flight trajectory measurement, the flight trajectory of the ball was measured by a high-speed camera and its speed was controlled by an ejector. The landing position of the ball was found to be strongly influenced by the shape of the panel; PIV measurements revealed the detachment of the ball. The air hole also moved the position of the detachment backward. The influence of panel shape shown by the hydrodynamic force measurement was consistent with the results of the trajectory analysis, revealing the importance of panel shape in serving.