Aerodynamics characteristics and flight trajectory of floater serve of volleyballs

Abstract

In Volleyball, the phenomena that the orbit changes unpredictably without rotation, attract attention. The investigation of these phenomena is important because of the score in game. Many studies have been carried out to clarify the aerodynamics characteristics of volleyballs and the mechanism of orbit changed irregularly. The aim of this study this study is to make clear the relationship between irregular orbit change and the ball speed, and the flight stare of the volleyballs. Firstly, the ball speed when the orbit change irregularly is measured by using 2 high speed cameras. A ball slightly turned when the orbit of the ball changed irregularly. Secondly, the drag coefficient and side force coefficient of balls are measured by wind tunnel experiment. As a result of that, the irregular orbital change was found to be seen in an area of critical region. We confirm a change of the side force coefficient in this area.