Thanks I will do that. ? where do I get the needles and what size this hand sewing has got knobs on it and I still have another sail to change. Cheers AUS230
Nice Sails! This is where I estimate the Centre of Area. You will have to decide where you think the Centre of Effort will be, but it most likely will be at that height, and some where ahead of that point, but how far ??
Clem The mast step is at 10% but I can rake the mast back to 15%. I am not sure how this all works but it seemed to be well balanced at Lake Lefrroy. any advice is appreciated. Cheers aus230
Recently I was talking to a 2nd year Uni student doing Aero engineering and was directed to wikipedia for answers to the questions....
The concept of the aerodynamic center (AC) is important in aerodynamics. It is fundamental in the science of stability of aircraft in flight.
For symmetric airfoils in subsonic flight the aerodynamic center is located approximately 25% of the chord from the leading edge of the airfoil. This point is described as the quarter-chord point. This result also holds true for 'thin-airfoils '. For non-symmetric (cambered) airfoils the quarter-chord is only an approximation for the aerodynamic center.
I have applied the Paul Day mathematical principal of sail centering to the above sails and have reached the conclusion that i may be adding another second place trophy to my collection in january However I havent factored in luck and punctures for either of us ,so the result cannotyet be confirmed
