Pros and Cons of Wing Sails[]
Type of Sail | Pros | Cons |
---|---|---|
Wing | Efficiency Durability Invertible |
Heavy |
Soft | Simplicity |
Forces not easily quantified |
Wing sails present an opportunity to increase efficiency, by offering greater lift and lower drag than soft sails of comparable size. The "cost" of the wing is a higher weight and higher centre of gravity, leading to an increase in pitching and heeling moments. However, the tip of a wing can be inverted, ie given reverse-camber, to generate lift that positively effects heeling moment.
Also of interest is the relative simplicity of quantifying a wing's performance, or estimating performance during the design stage. Aeronautical engineers have a wealth of knowledge available that relates to wings. Less information is available about the design and optimization of small sails.
For 2010/2011, the team decided to go with a soft sail, as the monohull design could not handle the estimated heeling moments presented by the wing. In the future, MAST will continue to investiate multihull designs, with the intent to incorporate a wing.