The Use of Mathematics in Designing Better Surfboard Fins Can Give Your Performance The ‘Lift’ It Deserves!
Did you know that the tiny little fin at the end of your surfboard can influence over 40% of your performance on the waves? The fin on your board can help you with stability, speed, and performance. Over 2.5 million surfers hit the beaches every day since 2016 in the US alone, but how many know about the structure of their surfboard or the use of the fins?
photo/ Brocken Inaglory
Oceans and seas can be unpredictable just like the weather and the waves. The only way a rider can pump out consistent performance day after day is by investing a little thought, study and research in the sport. Watersports depend a lot on the science of fluids and motion. While most sporting activities usually counter the forces of gravity, drag, and inertia, watersports have to deal with a plethora of simple and complex natural forces that determine the outcome of an event. Examples can be found in NRS SUP boards which are designed with various fin setups that interact differently with hydrodynamic forces.
What is the problem with the popular surfboard fins?
In most cases, even the professional surfers choose surfboards by brand value or by celebrity influence. Several brands in the market get celebrity surfers to endorse their products. Often, the choosing process involves “Oh, so-and-so star-surfer uses this board, so I must use it too.” If only choosing surfboards were as easy as selecting a car. A car has its features in the brochure, and you have the manual to keep it in the best shape. It is easy to drive a car, and it is likely that the same model will offer the same performance in the hands of different drivers. However, the same surfboard can perform differently for each surfer who tests the board out. Finding a universally best surfboard is nothing less than impossible. Even the slightest change the shape and size of the fin can affect the overall performance of the surfer.
Why is finding the right surfboard fin challenging?
Sadly, several manufacturers are either out of touch with the science of design, engineering, and hydrodynamics or they refuse to give due importance to design and focus on marketing gimmicks. The Cranfield University recently led a study to elicit how the fin design can influence the fluid dynamics and the peak performance of a surfboard.
Reportedly, two primary forces work on the board while it is catching the wave –
Lift: It is the side of the surfboard that faces the direction of the waveflow and experiences a higher pressure than the other side. The difference in pressure acts like a gradient and pushes the surfer towards the region of lower pressure. It results in a lift. It is also the same force that stabilizes airplanes and sailboats.
Drag: According to Newton’s third law, every action has an equal and opposite reaction, and drag is the equal and opposite reaction created by lift. It is a decelerating force that acts on the board to slow it down.
Therefore, fins that are results of extensive research and study can counter the process of drag and maximize lift performance.
A scientific guide to the right surfboard fin style, shape, and size
The research team at Cranfield University, led by Professor Zeeshan Rana, has helped to craft an ideal fin design that they modeled from a thorough study of fluid dynamics and aerospace engineering. A little explanation can help you understand that it is not farfetched at all to cue in the principles of aerodynamic design in the domain of surfing.
According to this team of brilliant engineers and researchers, the currents act on the board precisely like air current (and air pressure) works on the airplane wings. It has led them to design a modeling system that can create fins for surfboards based on the ideal drag to lift ratio. Since all of this began as a computer simulation, there is much skepticism about this process. However, further research has led to 42 different renditions and a super fin that generates a 14.32 lift to drag ratio.
A fin for the finishing line
The top SUP boards come with fins that conform to trendy colors and styles. Very few of the leading surfboard companies put in enough thought while designating fin depth, sweep or rake, foil and the angle of the fin that points towards the stringer. This kind of research in the world of surfboard design or fin customization is genuinely lacking even in 2018. The top surfers from around the world have tested the 3D printed fins and certified their effectiveness. Although the change in the shape, size or depth is so minute that even the most seasoned surfers cannot notice them at first glance, the scientifically produced fins can improve one’s performance by over 40% with the help of simple math.
Author: Charlie Brown
