A-29 THE INFLUENCE OF WIND UPON 3-DIMESIONAL TRAJECTORY OF GOLF BALL
Details
Aerodynamic forces and torque acting on the ball were measured under various flight conditions in a wind tunnel flow. Using the aerodynamic force coefficients, mathematical calculation of flight trajectory equation was made by time integral calculus, and 3-dimensional flight trajectory, changes in velocity as well as rotation velocity were obtained. Furthermore the logarithmic law was applied to trajectory formation of a golf ball in order to include influence of atmospheric boundary layer. The trajectory formation considering atmospheric boundary layer was verified by two experiments. One of the experiments was conducted to measure wind velocity distribution. The other was to compare the actual measured drop position with calculated data. Wind direction and velocity and initial condition of golf ball flight just after impact were measured to calculate. Flight trajectory considering natural wind was calculated by using 3-dimensional flight trajectory formation applied logarithmic law under various initial conditions in detail. As a result, we found out that there are conditions that distance reduces by tailwind and showed the conditions. In addition, we could get quantitative data: the influence of spin rate and launch angle including wind upon distance. Moreover we analyzed the quantitative influence of spin rate and launch angle including wind upon curving e.g. hooks and slices.
