I'll have to give that "twice as much air" at twice the speed concept some thought too.
Thanks for the insight... Norm S/V Bandersnatch Lying Julington Creek FL 30 07.72N 081 38.4W > [Original Message] > From: Kris Coward <[EMAIL PROTECTED]> > To: <[email protected]> > Cc: Arild Jensen <[EMAIL PROTECTED]> > Date: 2/5/2008 12:33:38 PM > Subject: Re: [Liveaboard] Wind Generator Energy (was: Look. It's aFreighter. It's a Sailboat. It's. Both) > > On Tue, Feb 05, 2008 at 10:13:37AM -0500, Norm of Bandersnatch wrote: > > Could be mass delusion. Could be that the wind generator sellers are > > trying to make their products appear more valuable than they are, a common > > larceny these days. > > > > For years we were told that airplanes fly because of the vacuum generated > > on the top of the wing, only lately have they admitted that the great > > majority of lift is pressure on the bottom of the wing. (Flat-winged model > > gliders do fly.) Sounds like they were trying to capitalize on the "gee > > wizz" factor of the suction generated by the Bernoulli effect of the wind > > over the curved top of the wing while ignoring the fact that several more > > times lift is due to the pressure on the bottom. > > Well vacuum can only get as large as ambient pressure, since it's just a > removal of said pressure. Strictly speaking, the plane is lifted > entirely by pressure on the underside of the wing, it's just that some > of it is ambient and therefore ordinarily balanced out by pressure on > the top of the wing. > > > As for the wind generator question, for me, E=MV^2 is still a valid law of > > physics. When the wind doubles in speed, the wind contains four times the > > And here I thought that it was E=1/2 mv^2 :) > > > energy. If the wind generator is 100% efficient and extracts all the > > energy possible then the output also goes up four times. I will not > > believe the cube thing until I see it proven clearly enough for my mind to > > accept it. > > In order for the relation between E and v to remain quadratic, m needs > to be constant with respect to v. Given that twice as much air blows > past you in a 10kt breeze than in the same period (with the same > temperature and pressure) in a 5kt breeze, I think it's fair to assume m > to be proportional to v and therefore provide the claimed cubic relation > (though I almost didn't catch that myself). > > Cheers, > Kris > > -- > Kris Coward http://unripe.melon.org/ > GPG Fingerprint: 2BF3 957D 310A FEEC 4733 830E 21A4 05C7 1FEB 12B3 > _______________________________________________ > Liveaboard mailing list > [email protected] > To adjust your membership settings over the web http://www.liveaboardnow.org/mailman/listinfo/liveaboard > To subscribe send an email to [EMAIL PROTECTED] > > To unsubscribe send an email to [EMAIL PROTECTED] > The archives are at http://www.liveaboardnow.org/pipermail/liveaboard/ > > To search the archives http://www.mail-archive.com/[email protected] > > The Mailman Users Guide can be found here http://www.gnu.org/software/mailman/mailman-member/index.html _______________________________________________ Liveaboard mailing list [email protected] To adjust your membership settings over the web http://www.liveaboardnow.org/mailman/listinfo/liveaboard To subscribe send an email to [EMAIL PROTECTED] To unsubscribe send an email to [EMAIL PROTECTED] The archives are at http://www.liveaboardnow.org/pipermail/liveaboard/ To search the archives http://www.mail-archive.com/[email protected] The Mailman Users Guide can be found here http://www.gnu.org/software/mailman/mailman-member/index.html
