Sail Design

Sail design process

Racing – Cruising – One Design



1.  Geometry – work out the sail plan and the basic over all sail seizes for each sail

2. Design – from the sails areas worked out,  build the designs of the sails, and work out the best designs from experience.

3. 3D Layout – from here we refine the designs by building a 3D mould of the boat and the sail set up on the boat. Form here we can refine the design and geometry of the sails and the design.

4. CFD – form there we take the sails for CFD analyzation, this refines the boat sail design further and what the righting moment of the sails product. 

5. VPP – Rans – this is then fed back to the Yacht designer, who in turn reruns the VVP for the boat. This is run will boat moulding design soft wear. To create the update VPP for the boat.

6. Membrane: we produce the membrane from this refined and developed sail,   

7. sail analyzation, is then done form this sail design on the water.

8.  Design views. One of the most critical parts of designing sails is the 3D design view, as it give the designer a clear view of how the sails look and fit on the boat.


List of Designs. Pat Considine – Des McWilliam  – Goren Sandberg – Stonelight Tong – Geoff Bishop

A: Velocity Prediction Program (VPP) and Computational Fluid Dynamics (CFD)

B:  Rans – CFD,

There are 2 main types of CFD,

Laminar flow paneled mentioned.:

Its very quick and takes about 3 mins to run an analyzation of the sails going up wind. This is very fast and productive. 60 degrees awa

The sails are set on the rig. And the sails are analyzed at 6 or 8 different heights on a cross sectional plane. this is very quick as the designer can make changes and rerun the analyzation again and get the answers quickly.

Rans :

Rans is a code which you need to pay a licence for. Its about 35 k per year.

Is a far more complex program and it takes a very long time to run at least a day per session. Its take the data in X – Y and Z plane.

It takes all the analyzation in every angle. Deta in every angle is worked out.

Wave hight. Angle boat heel- sail type and size.

A massive amount of information is put into the computer to get out the bastic deta. Not every company has the ability to do this. Only 2 that I know run it. And they only run it for the Americas cup or something like that. example.


Moudles high speck. Design views. 

On the left is a computer 3D rendering of a Light No. 1 Genoa design. On the right is the same sail flying. The design and the completed sail a re virtual match.

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