Abstract
Nowadays various type of breaking ball is used in sports. These breaking balls impact the outcome of the game. There are many researches on aerodynamics characteristics of various breaking ball. However, the effect of surface structure to the flow characteristics of a moving ball with rotation is still unknown. In this paper, the effect of the surface structure of ball to the aerodynamics characteristics of the ball is investigated by using wind tunnel experiment. Furthermore, the flow characteristics of four kinds different soccer balls and three kind of different model balls are investigated. These balls were made by 3D printer. It is claritied that the JABULANI's lift coefficient was lower than other soccer balls. Furthermore, the drag coefficient of the model balls become bigger in super critical region as the grooves become deeper, the lift coefficient of model balls were not change.
