On the shuttleworth on seakeeping page (just before the upwind ability bit, where he used wind tunnel results to assess the drag) is a formula for static hull flying.
Replace the .5 x Beam x weight with beam and weight in the windward hull. For height of centre of effort draw lines from each corner of the sail to halfway along the opposite edge, tio get the geometric centre, then draw a line between them and the coe is on that line, biased towards the bigger sail. ie oif the main is double the jib, the lcoe will be 1/3 of the way from the main coe to the jib coe. Not exact, but near enough.
rob
On Thu, Apr 14, 2011 at 12:26 AM, Gardner Pomper <gardner@networknow.org> wrote:
I have been playing with stats for my designs, trying to get the SA/D and Bruce number up, but it doesn't help me in real life if I have to reef when the wind hits 4 knots <grin>. How do I calculate the location and magnitude of the force on the sail, so that I can determine what wind speeds I need to reef at, or take the sails down altogether? I am willing to ignore the effect of the mast bending and use that as a safety factor.- GardnerPasadena, MD
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