One the basis that your windspeed below is true windspeed then you have to make adjustment for apparent windspeed.
Apparent wind sailing at 18kts in 15kts of wind @ 50 degrees to true wind is 28kts and more reasonably producing heeling force 6600N. A boat able to exceed windspeed will have apparent windspeed almost double true windspeed over a reasonable range of its polar. Force is obviously a function of the Cl but the schooner rig should be capable of generating a Cl of 1.2.
The problem with increasing mast height is that the pitching moment increases. Based on the previous email you would be thinking about reefing in winds above 15kts.
On 14/05/2016, at 3:42 PM, "lucsimard@ymail.com [harryproa]" <harryproa@yahoogroups.com.au> wrote:
I have been running some numbers, I quickly calculated the weight transfer to lw due to heeling moment, unless the heel force I got are wrong, it seem I either could benefit from have higher aspec ratio sails, more sail area or move weight to the lw hull ... since even at higher windspeed, there is a big part of the weight on the ww hull.
Increasing AR or sail area would surely mean a taller mast, I liked having 1 piece 40' masts for trailering, not sure how complicated longer 2 pieces carbon masts would be to homebuild ...Any comment on those would be much appreciated ...Sail area (m2) 50Wind speed (knots) 2 4 6 8 10 12 14 16 18 20Heel force (kgf) 2 10 23 41 63 94 126 164 211 258Heel moment (kg*m) 13 65 150 267 410 611 819 1066 1372 1677Sail Drive (kgf) 1 4 10 18 27 40 54 70 90 111
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Posted by: Rick Willoughby <rickwill@bigpond.net.au>
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