need articles- oftopic
Heikki wrote:
sinisa wrote:
If anyone have some (free) articles/tutorials/any kind of text related
to Sailboat Performance Prediction, please send me via mail, or tell me
where can i download it.
Get to your local library (if you have one) and get them to get hold of Dave
Gerr's book "The Nature of Boats". Read the chapters about performance
prediction on motorboats, and the following one on sailboats, so you
understand the formulas of his VPP (velocity prediction program).
As an example, he mentions that
"5000 square feet generates (very roughly) 100 horsepower in force 4
breeze. Thus, a Laser with 76 square feet of sail is running on a 1.5 hp
engine in force 4. This does not seem like very much, until you realize
that, with one crewmember, the whole vessel weighs only 275 pounds. The
result is over over 180 pounds per horsepower and, using standard
powerboat formulas, predicts a speed of 11 knots."
There are tables for what to expect of power per square foot of sail, and
how much speed to expect that power to make, for planing and displacement
boats. And a lot more... if you are seriously interested, you may want to
own the book.
Regards
Heikki
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