Host: The Japan Society of Mechanical Engineers
Name : [in Japanese]
Date : November 12, 2022 - November 13, 2022
When In volleyball, the air flow around the ball causes the ball to change direction. Comparing various balls, the ball bends, shakes, and falls differently. This is because the surface finish of the ball, the groove depth of the panel, and the panel shape change not only the surface flow but also the AC pattern, resulting in different aerodynamic characteristics for each ball. Therefore, ball performance research can lead to the development of the game, as knowledge of the ball's characteristics can give rise to new tactics. The serve is said to be the most offensive play because the player can raise the toss at his or her own timing. In this study, we focused on the jump serve, which has a high scoring rate on the serve, and obtained data on the flight trajectory, differences in aerodynamic characteristics, and force applied to the ball from groove measurements, ejection experiments, and fluid force measurements to obtain data for improving technique and coaching ability. In addition, to clarify the air flow around the ball, the separation point was visualized by 2D-PIV measurement. From the results obtained, it was confirmed that the ball lands in front of the surface as the number of rotations increases, but that it does not land in the court unless more rotations are applied depending on the ball, indicating that the surface and panel shapes have a significant impact on the flying trajectory.
