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sail horsepower?
Is there a formula relating boat sail area, wind speed, and horsepower? The best I can find at the public library are some ranges, ie hp/sq ft of sail area = 0.015 @ 7-10 kt 0.020 @ 11-16 kt 0.040 @ 17-21 kt 0.070 @ 22-27 kt I'm trying to get a better idea of how much sail I'd have to put on a light 15 foot plywood cabin cruiser with appropriate underwater shape, whose total weight with one occupant and a week's gear (including accumulated human waste) is 630 lb., to get it to plane in less than a full gale. TF Jones says 1 hp to plane each 40-50 pounds. For comparison, the above table applied to an Albacore racing dingy (250 lb) with two people aboard (300 lb) and 125 sq ft of sail says the wind has to be off the above scale for the boat to plane. I also found general wind power formulae in books at the library for generating electicity but there are constants in the formulae, eg efficiency, which I don't know for boat sails. I've looked at numbers for several racing boats of about the same displacement in library books to compare sail sizes but I'd like to do the calculation for this boat if I can manage it. -- ------------------------------------------------------------------------------ William R Watt National Capital FreeNet Ottawa's free community network homepage: www.ncf.ca/~ag384/top.htm warning: non-freenet email must have "notspam" in subject or it's returned |
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