Gardner
I have corrected the mast height and updated the polar in your ToyyoT folder. It is now closer to your target of 15kts in 15kts true wind. Easiest way to get there is probably to make the rig taller with the same sail area but I will also take a closer look at the hull drag and hull shapes. I use regressions to approximate the resistance over the wide range of conditions to generate the full polars. I can check that the hull drag results from the regressions near your target condition are close to the Michlet drag data that the regressions are based on. This allows me to fine tune the regression factors around your target speed.
I do not have any automatic reefing in the model. I just reduce the rig lift coefficient to avoid capsize - similar to flattening the sails. The ww hull is never permitted to lift completely. The windward performance may be better at higher wind strength with reduced sail area.
The most significant weakness I see with the design is resolving the rudder forces with the geometry you have. The trailing one will see more than 1/2 tonne side force when you are pushing it along.
The performance will be degraded once the superstructure starts ploughing through wave crests.
Rick Willoughby
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