golf

Golf ball drag reduction by dimples

Golf – precision club and ball sport in which competing players (or golfers) use many types of clubs to hit balls into a series of holes on a course using the fewest number of strokes.

It is one of the few ball games that does not require a standardized playing area. Instead, the game is played on a golf course, generally consisting of an arranged progression of either 9 or 18 “holes”. Each hole on the course must contain a “tee box” to start from and a “putting green” with the actual hole, and there are various other standardized forms of terrain in between such as the fairway, rough, and hazards, but each hole on a course and indeed among virtually all courses is unique in its specific layout and arrangement.

With the first recognizable form of the game of golf being played in Scotland in the early 1400’s, the golf ball has had nearly 600 years to evolve.

golf ball – a special ball designed to be used in the game of golf. Under the rules of golf, a golf ball weighs no more than 1.620 oz (45.93 grams), has a diameter not less than 1.680 in (42.67 mm), and performs within specified velocity, distance, and symmetry limits.

Fairway wood positioned near golf ball

Golf clubs

  • fairway wood
  • iron
  • putter

Golf Ball Dimples
Today, golf balls are easily recognized by their dimples – the indentations all over the outside surface.

  • Ask – As early as 1905, golfers realized that older, irregular golf balls were going farther than new ones. Why would that happen? How could golf balls be improved to take advantage of this discovery?
  • Imagine – English engineer William Taylor made systematic tests to determine what surface formation would give the best flight. Why did the irregularities improve the flight of the golf balls? What indentations provided the best results?
  • Design, Build – William Taylor then developed a pattern consisting of regularly spaced indentations over the entire surface, and later tools to help producing such balls in series. Taylor registered a patent for a dimple design in 1905.
  • Improve – Most golf balls on sale today have about 250–450 dimples, though there have been balls with more than 1000 dimples. The record holder was a ball with 1,070 dimples—414 larger ones (in four different sizes) and 656 pinhead-sized ones.

That’s engineering

  • aerodynamics – When a golf ball is hit, the impact, which lasts less than a millisecond, determines the ball’s velocity, launch angle and spin rate, all of which influence its trajectory (and its behavior when it hits the ground). A ball moving through air experiences two major aerodynamic forces, lift and drag. Dimpled balls fly farther than non-dimpled balls due to the combination of these two effects.
  • backspin – in almost every shot due to the golf club’s loft (i.e. angle between the clubface and a vertical plane). A spinning ball deforms the flow of air around it similar to an airplane wing. A backspinning ball experiences an upward force which makes it fly higher and longer than a ball without spin would.

Engineering ideas

  • velocity, impact, launch angle, spin rate, trajectory, aerodynamic forces, lift, drag

Do it
Now it is your turn. Here are some challenges for you to work on…

  • design an experiment to test different gold ball surfaces.

Learn more…

  • History Of The Golf Ball – With the first recognizable form of the game of golf being played in Scotland in the early 1400’s, the golf ball has had nearly 600 years to evolve.
  • Golf – The rules of golf are internationally standardised and are jointly governed by the Royal and Ancient Golf Club of St Andrews (R&A) and the United States Golf Association (USGA).