抄録
Aerodynamic characteristics of some golf balls whose dimples have different depths were measured. As a result, it was found that the shallower the dimple was, the larger the lift coefficient was. However, when the depth of the dimples was much shallower, the lift coefficient was extremely-little on the slow velocity, i.e. under 28m/s. We searched for a golf ball with dimple patterns that had a high lift coefficient at all velocities. As a result, it was found that a golf ball with a dimple pattern that has extremely small dimples between large shallow dimples has a high lift coefficient at all velocities, including under 28m/s. In order to investigate the cause of the results, a flow visualization experiment was conducted. Visualization of flow around a golf ball was conducted by smoke wire method. Moreover pictures of flow were taken by high-speed video and we analyzed them by PIV (Particle Image Velocimetry). As a result, there was the difference in the streamline distribution between golf balls.
