Futures Fins Computational Fluid Dynamics

At Futures Fins, they always look forward to advancing technology and improving products. With the latest advancements in computer power and simulation software, the time had come to include Computational Fluid Dynamics (CFD) in our product development loop. CFD is a technology where the water flow around fins can be simulated in a computer without the need to build a prototype. Therefore, using CFD, it is possible to estimate, compare, and modify the performance of fin designs even before hitting the water. Thanks to an exclusive partnership with RED Fluid Dynamics, CFD is now used at Futures Fins to help develop fins and to better understand how the fins work. The ultimate testing ground will always be the ocean, and your feedback is the most important performance scale, CFD is used to make sure you can ride the most technologically advanced fin system and shapes in the world. Ride the Future. Ride Futures Fins.

Water Flow

The way the water flows around your fin determines its performance. Using CFD, you are able to visualize the water flow and measure relevant quantities, such as pressure, velocity and turbulence, that contributes to the performance of the fin. Flow visualizations and performance evaluation are carried out from low angles between the fin and the water flow, representing your take off where the water flows is attached to the fin surface, to turning angles up to the fin release, where the water flow detaches from the fin and your board spins out.

Visualization of the water flow around the fin for increasing turning angle, showing clean and regular flow at 10 deg. turn and separated and highly turbulent flow with release at 20 deg. turn.

Foil Performance

In Futures' founder Vince Longo's own words, “the pressure differences that a fin in motion makes are very, very real.” Using CFD, Futures Fins is able to quantify such pressure difference in every single part of the fin and use it to drive the optimization of new or existing designs. The foil shape is what influences pressure difference the most, with relative differences from foil to foil estimated by CFD simulations that can be as high as 30% during a turn.

Water pressure difference generated by different foils at 0 deg.; RED = HIGH PRESSURE / BLUE = LOW PRESSURE

Average values of drag, lift, and efficiency (lift/drag) during a turn for different foils.

Template

Surfing Style • Drive vs. Turnability

The rake of a fin has to do with how far the tip sticks out past the back of the fin base. The further the tip sticks out, the more Rake a fin has. Alternatively, the less the tip sticks out, the more upright the fin is. This specific CFD analysis measures the pressure map on our three template categories (Rake, Neutral, Pivot). Blue is low pressure and Red is high pressure. As you see below, the Raked fin has a much less concentrated pressure point (red) than the Pivot fin. This more equally distributed pressure throughout the Raked fin can equate to as much as a 12% increase in lift from a Pivot fin during the later part of a turn. This additional lift, or projection forward, accounts for the feeling of drive and drawn out turns in Raked templates. On upright fins, the pressure gets more concentrated in one place during a later part of a turn which gives less lift but allows for tighter turns and a more skatey feel.