Three-dimensional aerodynamics in volleyball jump serves

Abstract

In volleyball, the flight trajectory changes on the basis of the aerodynamic forces acting on the ball. Comparing various balls, the trajectory bends, shakes, and falls differently. This is because the surface finish of the ball, the depth of the grooves in the panels, and the shape of the panels change not only the surface flow but also the wake pattern, resulting in different aerodynamic characteristics for each ball. Therefore, ball performance research leads to the development of competitions, as new tactics are created by knowing the ball's characteristics. The serve is said to be the most aggressive play because the player can raise the toss at his or her own timing. In this study, we focus on the jump serve, which has the highest scoring rate among the serves, and obtain data from injection experiments to investigate the flight trajectory from time to time, differences in aerodynamic characteristics, and the force applied to the ball, as well as to propose a ball that best reflects the skills of the players. As a result, it was found that as the angular velocity increased, the ball landed in front of the player and the amplitude of the coefficient of lateral force decreased. The surface shape was found to be highly dependent on the flight trajectory of the ball, as the point at which the ball lands and the force applied to the ball differ depending on the surface shape.