Do you play golf or have you ever held a golf ball in your hand?
Then you will probably have noticed the rough surface with the many small dimples.
Why do golf balls have dimples?
Short answer: Golf balls with dimples fly further than smooth golf balls.
But why do golf balls with dimples fly further?
This is where physics and fluid mechanics come into play.
The dimples on the ball create many small turbulences in the air around the ball. Together, these swirls then form a kind of protective layer in the air.
In contrast to a smooth surface, the braking turbulences behind the ball are thus significantly reduced.
As a result, the golf ball travels more aerodynamically and flies more stable and thus further through the air.
Tests have shown that dimpled balls fly twice as far as balls without dimples.
This increase in flight performance has changed the sport. Today, professional golfers can hit balls way over 300 yards.
It is these distances that make it possible to complete holes of more than 500 yards with only 5 strokes or less.
How many dimples does a golf ball have?
Most modern golf balls come with 300 to 450 dimples, and the exact number varies between brands and models. For example, Titleist's most popular golf ball has 388 dimples, while the tomorrow golf ball features 352 dimples.
After years of research, it has been found that the number of dimples within this range is ideal for optimizing aerodynamics during ball flight.
With fewer dimples, the individual turbulences become too large, and when using too many dimples, the surface becomes too smooth and the desired effect fizzles out.
The exact number and arrangement of the dimples varies from brand to brand.
There are also no predefined rules for this. Entire R&D teams of the major golf brands work on further refining the golf ball design to improve performance.
How does the ball dimple pattern change flight and distance?
Dimples play a crucial role in golf ball design within the industry. After finalizing the ball design, spin rates are measured, and dimples are then tailored to optimize the ball's flight.
In the case of a higher spinning ball, designers tend to deepen the dimples to keep the flight trajectory lower. Conversely, for lower spinning balls, shallower dimples are employed to enhance the ball's ascent and prolong its time in the air.
Dimples function by disrupting the air around the ball during flight, influencing two key characteristics: Lift and Drag. Achieving the ideal dimple design involves a delicate balance between these two variables. Research teams experiment with varying diameters, shapes, total coverage, and edge angles to precisely control lift and drag.
A miscalculation in dimple design can result in a significant loss of distance.
That's definitely not what any golfer wants!
How do the dimples get on the golf ball?
Golf balls come in many different designs.
Usually, a modern golf ball consists of a rubber core and one or more mantle layers. Most of the time it is a 2- or 3-part construction.
The dimples are created during the so-called "injection molding" process. In this process, the rubber core is placed in a mold and the liquid mantle material is pressed into the mold.
The recesses for the dimples are worked into this mold as you can see in the image below.
This is how the golf ball gets its outer layer and the desired dimple structure.
After that, the ball is sanded, lacquered and the respective logo is printed on it.
Who came up with the idea of dimpled golf balls?
In the past, all golf balls used to be smooth.
Golfers started noticing, however, that worn balls with dents and edges fly much further. So people carved small hollows and patterns into the surface with knives.
It was only through this observation that manufacturers began to experiment with dimples in golf ball design.
As is so often the case in science, it was a lucky coincidence that led to new things.