Golf Ball - Dimple Dynamics
Supercomputer simulation shows the engineering of better golf balls. Credit: Arizona State University / University of Maryland / IMAGINOVA STUDIOS.
A golf ball is a ball designed to be used in the game of golf.
A regulation golf ball weighs no more than 1.620 oz (45.93 grams), with a diameter not less than 1.680 in (42.67 mm), and is symmetrically spherical in shape. Like golf clubs, golf balls are subject to testing and approval by the Royal and Ancient Golf Club of St Andrews and the United States Golf Association, and those that do not conform with regulations may not be used in competitions
When a golf ball is hit, the impact, which lasts less than a millisecond, determines the ball’s velocity, launch angle and spin rate, all of which influence its trajectory (and its behavior when it hits the ground).
A ball moving through air experiences two major aerodynamic forces, lift and drag.
Dimpled balls fly farther than non-dimpled balls due to the combination of two effects:
Firstly, the dimples delay separation of the boundary layer from the ball. Early separation, as seen on a smooth sphere, causes significant wake turbulence, the principal cause of drag. The separation delay caused by the dimples therefore reduces this wake turbulence, and hence the drag.
Secondly, backspin generates lift by deforming the airflow around the ball, in a similar manner to an airplane wing.
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