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flyinggorilla edited this page Jan 4, 2021 · 16 revisions

Sail-Trim Simulator

This simulator trims an A-Class catamaran to best fit calculated apparent wind. While this is an idealization, it comes close enough to get a better understanding of sail-trim. Basic sail-twist concepts apply to all other catamarans like Nacra 15 or Nacra 17 as well as dinghys such as Laser or RS Aero too, just ignore lack of jib of the former and mast rotation, traveller on the latter.

  • learn and understand true-wind vs. apparent wind and it's impact to sail-twist and trim
  • improve sail-trim on the water with better understanding of how much sail-twist, mast-rotation and traveler move is needed in certain situations
  • share simulator views as URL hyperlinks with others, as baseline to discuss real-world trim improvements

The simulator runs in your Web browser:


Quick intro on how to use this simulator:

  1. adjust true-wind speed in knots. it's direction is irrelevant for the simulation.
  2. adjust wind condition, stable thermal winds have higher wind gradient impact than gusty unstable winds
  3. adjust boat heading in degrees relative to true-wind direction - e.g. 50° for upwind, and 135° for downwind.
  4. adjust boat speed in knots that you estimate to fit to wind and heading. The simulated foiling A-Cat will fly at 13+ knots. Because it's a simulator, have also fun sailing practically impossible configurations.
  5. click share current view to bookmark your current view or share it as Web link with others

Next: Wind Basics