The Real Science Behind Golf Ball Dimples
Most people who play golf understand that the dimples on the ball serve some kind of aerodynamic purpose. But what exactly is going on as that tiny white plastic ball is flying through the air?
"A golf ball with dimples will go almost twice as far as a golf ball without," says Steve Quintavella, the United States Golf Association's (USGA) Equipment Standards Operations Manager. "A golf ball has dimples to reduce wind resistance and aerodynamic drag."
But how can a bumpy surface have less drag than a smooth surface? For a golf ball this is true because it is a round object. If the ball was smooth the airflow passing by would detach quickly behind the ball because it wants to follow the flow of air instead of the surface of the ball. This detached airflow forms a large area of low pressure behind the ball causing a lot of drag.
"That's almost like a vacuum," says Quintavella, "sucking the ball back and slowing it down in the face of the wind."
The dimples on a golf ball create a tiny pocket of air disturbance on the surface of the ball. This turbulence causes the passing air to remain attached to the surface of the ball longer. As the airflow wraps around the ball farther the size of the low pressure zone behind the ball is reduced. This reduces the drag of the ball as it passes through the air.
If the ball is rotating the dimples also affect the speed of the air passing by. The difference in speed means a difference in air pressure, and lift is formed according to Bernouli's Principle. Depending on the direction of the rotation this added lift can make the ball fly longer or turn left or right.
Still with me? Check out this video below by the USGA further explaining the science behind the golf ball dimple. It's a lot of science hidden in an otherwise simple looking object.