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Monday 14 February 2011

Rotating foils on Yacht Rigging - upwind sailing in only about 3 knots true wind

In this video we can see how the foils that we designed for Future Fibres, in Spain, work as we sail upwind, in only about 3 knots true wind speed.....

What is critical to the success of these foils is that each one is designed so that it creates to most efficient aerofoils shape (a NACA section) for that particular section of standing rigging.

This means that the drag from the airflow over each linear length of rigging is potentially reduced by as much as 75% when compared to the bare, circular rigging it covers. And because they are free to rotate 180 degrees, they will always line up with the airflow, as it changes over the height of the rig.

And perhaps whats more significant than the reduction in drag is the fact the downstream air flow is much less disturbed, and thus increases the potential power that can be produced from the mainsail. Where traditionally we can find that the airflow downstream of simple rod rigging may not have stabilised for some distance after passing the rigging, the flow over a foil such as these can be up to nominal speed some 20mm after passing the rigging.

And perhaps the last point to make here in this brief article is that they can be fitted to any existing (circular) rigging, and wont be penalised under IRC (at the time of writing...!)

In the following posts you can see how the foils work in more breeze upwind, and also how they work as we hoist and gybe an asymmetric genneker in light winds.....

For more information on these foils, contact Future Fibres in Spain, or take a look at their site at FutureFibres.com