| 摘要 |
<p>PURPOSE: To provide a golf ball of making possible to reduce an aerodynamic resistance when a ball is flying by composing of that a globe shaped outer surface has a plurality of dimples and the each dimple has the first and second concave portions and these concave portions are adjacent to each other on the circumference of the golf ball. CONSTITUTION: A globular shaped outer surface has a plurality of dimples and each dimple consists of the first and second concave portions and these first and second concave portions are arranged adjacent to each other. The first and second concave portions of the dimples have almost the same size and shape. For example, the dimple 10 having a diameter in range between 2mm and 5mm and a depth in range between 0.1mm and 0.3mm has adjacent two concave portions 11 and 13, and these two concave portions are divided by a dividing portion 12. The dividing portion 12 has a height in range between 0.05mm and 1.3mm. The edge portion of the first concave portion causes the division of a boundary layer and an air stream passing through the second concave portion causes re-joining of the boundary layer.</p> |
