New 3D fins in stock . With the "dimple" technology and superior flex memory these are good ! Designed for speed , flow and hold ! Check them out at the online store here ! Scroll below to read and watch a video about the design principles !
As we all know, a golf ball with dimples will fly further than a golf ball without. What most of us don’t know is why? There are two main reasons:
The Dimpled Surface reduces drag.
The Dimpled Surface improves lift.
A lesson in Hydrodynamics
There are two types of flow around an object: laminar and turbulent. Laminar flow has less drag, but it is also prone to a phenomenon called “separation.” Once separation of a laminar boundary layer occurs, drag rises dramatically because of eddies that form in the gap. Turbulent flow has more drag initially but also better adhesion, and therefore is less prone to separation. Therefore, if the shape of an object is such that separation occurs easily, it is better to create a turbulent boundary layer in order to increase adhesion and reduce eddies (which means a significant reduction in drag) Dimples on golf balls create a turbulent boundary layer.
3DFINS decided to test these principles and apply them to a surfboard fin. With advanced Computer Fluid Dynamic testing, we compared two identical fins: the 3DFINS dimpled fin and the exact same fin without dimples. The tests were conducted by fluid dynamics expert Darren Stephens (formally of CSIRO) and the results were surprising. A surfboard fin with a smooth surface is much like a golf ball with a smooth surface, it has a lamina flow over the surface. This works quite well when going straight and at lower speeds, but when you start to turn and reach higher speeds the fluid starts to separate from the foil or fins surface.
A surfboard fin with dimples creates a turbulent flow. Turbulent flow has more adhesion so when you start to turn, the dimpled fin surface delays the flow separation, reducing the separation bubble allowing the foil to maintain performance.
When the surfer is turning at high speeds, the turbulent boundary layer helps the flow overcome an adverse pressure gradient and allows the fin to remain attached to the surface longer than it would otherwise. This reduces drag, increases lift and improves overall performance of the fin design.