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MAKANIFINS - Humpback Whale concept for windsurfing fins

Objectives

The 3 main objectives for this fin design:

• Reducing spin-out as much as possible
• Optimizing the upwind capacity (Angle & Speed)
• Radical manoeuverability

Nature &Research 

Different elements in nature have always inspired us at Makani Fins. Different fish fins, and studies related to them, inspire us to use the proper foil with the best thickness distribution in the 2D Outlines for our designs. The idea behind our fin’s design was hugely inspired by the leading-edge of the humpback whales’ flipper. By reading different past research, and through our collaboration with Mr. Fish himself, we realized how challenging it would be to immerse this

Past research specifies that the presence of sinusoidal protuberances on the leading-edge of the whale’s flipper causes a lift that is 50% greater than the stall angle of a classic leading edge. The next images show this theory and effect with different amplitudes.

The mechanism behind this effect:

The tubercles generate a flow pattern that produces vortices, they have a particular spin that causes the flow going over the tubercle to be energized and accelerated in order to maintain the lift of the fin at high angles of attack.

This Concept applied on our windsurfing fin

There are many advantages of the presence of sinusoidal protuberances on the leading-edgeofthe windsurfing fin.

-It won't stall (no spin-out) when you increase your angle of attack.

-The rider will then be able to go upwind like they never have before.

-High increase in manoeuvrability, with the ability to do radical curves on the board without losing the lift of your fin (as you would normally occur when you spin-out).

 

The 3D generic design

The flexible 3D model allows us to perform accurate numerical and technical tests. The 3D model allows us to easily modify various input data, such as; amplitude, frequency, foil, (etc..). Our generic 3D model has been built to optimize HB design and prototyping.

Evolution & Optimization

We are in the process of pushing this concept even further, and we are working hard to do so. The HB Concept is the first to be in production, and we are now introducing the PIRANHA. We improve our knowledge a lot through our prototypes, testing feedback, and collaboration with the lab. We continue to actively seek new information to learn, and our ultimate goal is to optimize all of our designs relative to their specific uses.