Mathematical Modeling and Surf Boards

Surf boards have so many variations depending on what you want and what type of surfer you are but how much of the design is based on scientific or mathematical research?

A lot of the adjustments and choices are based on how well various surfers do.  The idea is that if it worked for them, it should work for everyone.

Considering over 2.5 million surfers in the United States in 2016 which was up 40 percent from 2004, interest in the scientific community has also increased.

In 2017, Cranfield University in the United Kingdom published a report in the Journal of Sports Engineering and Technology explains the results of their mathematical modeling of fins on a surfboard.  The fin is the small curved piece sticking off the bottom, and a surfboard may have one, three or four on the bottom.

They explored the idea that fluid dynamics could be modeled to model the peak performing fin because the fin is what helps surfers maneuver through the water while accelerating.  The fin causes it to go faster and to grip the wave giving them more control, or in other words it is a type of lift. Surfers want fins that emphasize lift while eliminating as much drag or slowing as possible.

The people who carried out the study decided the fin operates in water the same way the airplane wing works in air so they can use aerodynamic mathematical modeling to try to find the precise shaped fin that produces the most lift with minimal drag.  Beginning with the standard shape, they calculated lift to drag ratios before making adjustments to shape, thickness, depth, length, base shape, and curve until they created a fin with a 14.32 lift to drag ratio. This was a 62 percent increase over the original.

It took them 42 different iterations before they arrived at the final ratio.  In the overall scheme of things, the changes may not make much difference to the average surfer, this could make a huge difference to the professional for whom the smallest change can make a difference.  This is cool to know they can use fluid dynamics and aeronautics to lean more about the "perfect" fin.

Another man, Bowen,  due to the frustration of having to buy a board every 6 months or so because the boards would split, did some research and revamped the basic surfboard which lead to him starting his own surfboard company.  The normal technique is to place a piece of balsam wood in a piece of polyurethane foam.  This blank is then shaped into the proper surfboard shape before being finished.  Bowen revamped the traditional way of making surfboards by making his with layers because the layers give more flexibility making them more dynamic and less likely to break.

Let me know what you think, I'd love to hear.  Have a great day.