The golf ball is a small and humble device with crude beginnings dating back to the 1500s. The first ball that would be recognizable as a golf ball today would be the dimple pattern first used in 1908. While a golf ball today may seem similar to those from 100 years in the past, the mechanics could not be more different.
Beating The Air
A golf ball having these small dimples in may seem like it is more for textural purposes when in contact with different natures of ground material, but they play a very big part in how a golf ball flies as far as it is able to fly. There are three main areas of effect that the dimples have on the surrounding air when we hit a golf ball.
Turbulent Boundary
When a golf ball is initially hit, it goes through its first stage of rapid acceleration, during this stage of rapid acceleration we start to see the effects of a turbulent boundary. The turbulent boundary remains intact until approximately halfway through the ball’s flight. Flying at high speeds, the dimples on a golf ball start to create smaller vortices in each of the dimples.
The small vortices create what is in essence a small, higher-pressure zone around the leading side of the ball. The high pressure around the leading side of the ball minimizes air resistance to a point that a dimpled ball can fly on average 20% to 30% further than a completely smooth ball. Another positive effect of having this air boundary is that the ball is less influenced by any potential cross winds. Dimples create a ball that not only fly further but also are more accurate than a ball of any other shape, despite any potential cross winds.
Turbulent Flow
The turbulent flow exists throughout the ball’s whole travel but comes especially in to play around halfway through the ball’s travel, when the turbulent boundary starts to fade. The turbulent flow refers to the low-pressure zone left in the ball’s wake as it cuts through the air. The dimples create a turbulent effect in this low-pressure zone, meaning the low-pressure zone is minimized, causing less overall drag on the ball.
Magnus Effect
Once the turbulent boundary has dissipated, the spin of the ball now has more of an effect on the surrounding air. When we look at the normal loft angle of a golf club, it makes sense why the ball would naturally have a backspin to it.
The dimples on a golf ball start to pull the air towards the top side of the ball, creating a faster air velocity on the top of the ball. This is where we come to Bernoulli’s principle, which teaches us that as the air velocity decreases, the air pressure increases. The air velocity on the ball, now lower at the bottom, creates a higher-pressure zone below the ball. This high-pressure zone acts as a force pushing upwards on the ball, fighting the gravity pulling the ball back down to the ground.