Dutiful Dimples

My best friend from high school is a committed golf player. I have yet to develop an interest in the game, and he hopes that I would, one day. I too, hope so, having heard much about the inner game of golf from Major Tham.

Having come across some interesting reads recently, I would like to talk a little bit about the golf ball and a small design feature of it. If you have ever picked up a golf ball, you will notice that it is dimpled, and that it is not as smoothly spherical as a ping pong ball.

The texture feels good, and one would naturally be led to think the dimples are for tractional/frictional purposes: in other words, to prevent the ball from rolling too much on the green. The purpose of the dimples is, in fact, to disrupt the airflow on the surface of the ball as it flies hundreds of yards to fetch you a birdie.

The turbulent layer caused by disrupted airflow does not sound beneficial aerodynamically, but in reality this very thin turbulent boundary layer actually energises the laminar boundary layer over the curve of the ball, thereby delaying the separation of airflow from the surface of the ball in motion.

The result of this is a smaller wake, and a reduced drag. With reduced drag, the ball can travel a further distance than the one without dimples would. Now, doesn't that make good aerodynamic sense?

Wrote this swiftly based on whatever I recalled from the readings, so should there be any misses or corrupted explanation, do let me know.

The diagram on the side illustrates the above-mentioned point with exceptional clarity.