OK, it was always gonna happen. Kelly digs golf, so someone put two and two together and got what might be a five. Surfboard fins that are like golf balls. Yah, seri-ass. Stuck some dimple action onto the fin surface and boom, the world's (supposedly) fastest fin is born.
Bunch of ou's in West Oz came up with the concept and launched 3D Fins. ASP surfer Josh Kerr rides for them, so must be doing something right!
Their fins have Dimple Technology, as in dimples like a golf ball. It's meant to creates incredible drive, quick release through turns and sky burning potential.
Computer flow Dynamic tests have proven the dimples increase Lift/Drive significantly, giving the surfer the opportunity to gain more speed and with more speed comes the opportunity for more advanced maneouvres.
OK, so why dimples??
As we all now know, a Golf ball with Dimples will fly further than a Golf ball without. That's why golf balls have dimples. Not just cos they look cool.
Dimples surfaces do 2 things - they reduce drag, and improve lift.
First a quick lesson in Hydrodynamics (Aerodynamics). 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 turbulate the boundary layer in order to increase adhesion and reduce eddies (which means a significant reduction in drag).
Dimples on golf balls turbulate the boundary layer. So 3DFINScience decided to test these principles and apply them to a Surfboard fin. With advanced Computer Flow Dynamic testing 3DFINScience compared two exactly the same fins, the Moonrakerr Dimpled fin and the same fin design without Dimples.
The tests were conducted by flow dynamics expert 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 Laminar flow over the surface. This works quiet 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 cavitations (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.
Do they work? Who knows? But they sure look damn cool! Wanna grab a set? Easy - just hook past Surf Centre at the beachfront as their new stock of 3D Fins will be landing on Monday June 10th.
20 August 2013 - Dane Cox
I paddled out at Main Rights, there was a bit of chop yet they seemed to hold in the conditions and allowed me to put weight behind them even on the bigger ones. Later, I surfed Pipe, and found I could do a roundhouse cutback on almost any wave without having to wait in the foam to ride the turn out. If you can imagine a board that is sharp with its turning, quick off the bottom and quick off the top, Once you point your board, it goes without hesitation. It makes your board feel lighter, more maneuverable and responsive.
The best thing to do is to try them for yourself. It could be that the dimensions of my board and the fins are a good combination, but I just feel that I had one of my best surfs when using them. Good waves or bad, give them a try!