Quote: "Is there a way to covert windspeed and Sailarea into hp"
Yes, here is, as I remember it, the basic formula for the
power contained in wind: (You might want to verify it by asking an
engineer at a windturbine manufacturer's or some such)
P = Cp * 1/2 * rho * A * V^3 * k
Where:
P = Power output, kilowatts
Cp = Maximum power coefficient, ranging from 0.25 to 0.45, dimension less (theoretical maximum = 0.59)
rho = Air density, lb/ft3
A = Sail Area
V = Wind speed, mph
k = 0.000133* A constant to yield power in kilowatts. (Multiplying the above kilowatt answer by 1.340 converts it to horse- power [i.e., 1 kW = 1.340 horsepower]).
Note that the value “Cp” ranges widely but cannot exceed .59. It is an expression of how much of the total power contained in wind a given extraction device, such as sails, can extract. This theoretical limit cannot be reached even by the most efficient very large wind turbines, much less by a sailboat's sails. This limit to extraction of 59% is known as the “Betz Limit” after the German physicist who determined it shortly after the Kaiser's War. I'm sure you'll remember that from you high
school physics
classes :-)
You can now set about figuring out for yourself how a rig should be designed to maximize Cp, but be careful, now, for Cp will vary with the Point of Sail, and is in part dependent (for every point of sail) on the rig having the optimum Aspect Ratio for that point of sail.
When you finish those considerations you can set about contemplating how each of the many coefficients that enter into designing the shape of the
hull affects the ultimate force that propels the
hull through the
water. Again, exercise some caution, for that determination needs to consider the momentary Angle of Heel.
I say with all possible respect: You cannot learn yacht design by asking us amatoors questions in the disjointed, unsystematic fashion you have been doing. I recommend most highly that you turn to an accredited educational institution such as, perhaps, Westlawn
School of Yacht Design. Be prepared for your tuition
fees amounting, before you gain your accreditation, to considerably more than the cost of a vessel fully found and ready to take you anywhere you might want to go, s.a. the
Denmark Strait, Cape Stiff and Rarotonga. This spring there was one such vessel, a thoroughly sound William Garden design built by what many, at the time of her building, considered the very best yard in this part of the world,
for sale in my marina. She
sold for Can$65K, I am told. Had I been forty years younger – i.e. had I been your age – she would have come to me!
Nochmals – viel Glück!
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