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On 3 Nov 2003 13:54:29 GMT, (William R.
Watt) wrote:

Rodney Myrvaagnes ) writes:
On 1 Nov 2003 13:28:49 GMT, (William R.
Watt) wrote:

no, there's got to be a formula relating wind speed, sail area, and
horsepower.
--

Such a formula could be generated, In fact, a vast family of such
formulas could be generated, all equally valid, and all giving
different results.

The assumptions required to generate such a formula swamp any results
that might be derived from it.

yes, but that's true of most things in nature and yet applied mathematics
works. for example, formulae are used to design aeroplane wings. the two
approaches used are to make the most appropriate assumptions and verify by
testing. the results only have to be accurate enough to be effective
design tools.

I am tryng to be helpful. The noise in the set of reasonable
assumptions will produce output noise many times the size of the
signal. An airplane wing is used in one medium away from boundaries.

You could empirically derive some formula from the performance of a
rogallo type hang glider well off the ground. It would, however, be
close to useless for predicting a sailboat's behavior in the real
situation of a water/air boundary, with its normally height-dependent
wind-velocity vector.

I hope the next questions don't offend.

How skilled a sailor are you?

Can you enter a local club one-design race and be fairly sure you
won't come in last?

Have you ever felt the difference a new sail makes?

Rodney Myrvaagnes NYC J36 Gjo/a

"Religious wisdom is to wisdom as military music is to music."