抄録
The bouncing motion of a solid particle on a wall in the water is different from that in the air because the water influences the particle motion more than the air. In order to investigate such effect of the water on the solid particle, bouncing behavior of a cylinder in the water was studied by image processing. In the experiment, an apparent coefficient of restitution of the cylinder was not unique, that is, it was influenced by the velocity and the rotating angular velocity of the cylinder. The velocity fields of the water suggested that the water flow around the cylinder played an important role on the bouncing motion.
