On the basis of a surface shape appearing at a predetermined point moment by moment during rotation of a golf ball having numerous dimples on its surface, a data constellation regarding a parameter dependent on a surface shape of the golf ball is calculated. A preferable parameter is a distance between an axis of the rotation and the surface of the golf ball. Another preferable parameter is a volume of space between a surface of a phantom sphere and the surface of the golf ball. Fourier transformation is performed on the data constellation to obtain a transformed data constellation. On the basis of a peak value and an order of a maximum peak of the transformed data constellation, an aerodynamic characteristic of the golf ball is determined. The peak value and the order of the maximum peak are calculated for each of PH rotation and POP rotation.
1. A process for designing a golf ball, the process comprising the steps of:
deciding positions and shapes of numerous dimples located on a surface of a golf ball;
calculating a data constellation regarding a parameter dependent on a surface shape of the golf ball, on the basis of a surface shape appearing at a predetermined point moment by moment during rotation of the golf ball;
performing Fourier transformation on the data constellation to obtain a transformed data constellation;
determining an aerodynamic characteristic of the golf ball on the basis of the transformed data constellation; and
changing the positions or the shapes of the dimples when the aerodynamic characteristic is insufficient.
2. The process according to claim 1 , wherein at the determination step, the aerodynamic characteristic of the golf ball is determined on the basis of a peak value and an order of a maximum peak of the transformed data constellation.
3. The process according to claim 1 , wherein at the calculation step, the data constellation is calculated throughout one rotation of the golf ball.
4. The process according to claim 1 , wherein at the calculation step, the data constellation is calculated on the basis of a shape of a surface near a great circle orthogonal to an axis of the rotation.
5. The process according to claim 1 , wherein at the calculation step, the data constellation is calculated on the basis of a parameter dependent on a distance between an axis of the rotation and the surface of the golf ball.
6. The process according to claim 1 , wherein at the calculation step, the data constellation is calculated on the basis of a parameter dependent on a volume of space between a surface of a phantom sphere and the surface of the golf ball.