A golf ball is one of the most recognizable designs in all of sports. It’s a small sphere about 1.68 inches in diameter. White is the most popular color.
What makes the golf ball unique are the hundreds of small impressions or dimples on its surface. Many people wonder why dimples exist. The answer is crucial to a golf ball’s flight.
Dimples decrease wind resistance on a golf ball as it flies through the air. Reducing drag makes golf balls fly much farther than they would with a smooth surface.
Early golfers first discovered this secret when they hit used golf balls. Golf balls with knicks and dings went three times as far as brand new ones. This realization led golfers to purposely gouge the golf ball’s surface.
How Dimples Work
As a golf ball flies through the air, the airflow interacts with the surface of the ball and greatly affects the amount of drag.
Wind meets the front of the ball and wraps around it. If the golf ball is smooth, the air flowing closest to the surface of the ball follows the flow of air around it. This pattern creates a detached airflow behind the ball.
The detached airflow creates a wake behind the ball, which in turn creates a low-pressure zone. This zone acts like a vacuum, sucking the ball backwards, causing drag, and slowing down ball speed.
Adding dimples to the ball changes how air flows over it. As the air travels over one of the dimples, a tiny pocket of turbulence or air disturbance is created on the surface. Instead of impeding the flight of the ball, these tiny pockets of turbulence allow the closer layer of air to travel tighter around it.
The low level of turbulence causes the air to become attached to the ball. A more attached airflow means there is a smaller wake, and thus a smaller low pressure zone which means less drag. Even a slight change in airflow can make a big difference.
Dimples on a golf ball also aid the flight of the ball by influencing the lift as the ball spins through the air. Lift force in aerodynamics is a concept known as Bernoulli’s Principle. The principle states that as the speed of the airflow is increased, the pressure on the airflow of the ball is decreased, creating lift.
The lift is pronounced due to the dimples on the ball which measure 15/100ths of a millimeter. There are no rules regulating dimple design on golf balls. There can be any number, and they can have any shape.
While dimple sizes, shapes, and effects may differ, they remain a crucial aspect of all golf ball design.