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Author Topic: interesting site  (Read 1052 times)

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edy252

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interesting site
« on: January 05, 2005, 10:21:41 AM »
hi


found an interesting site:


http://www.speakerfactory.net/wind.htm

« Last Edit: January 05, 2005, 10:21:41 AM by (unknown) »
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RatOmeter

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Re: interesting site
« Reply #1 on: January 05, 2005, 04:04:21 AM »
Not again!
« Last Edit: January 05, 2005, 04:04:21 AM by RatOmeter »
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tecker

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Re: interesting site
« Reply #2 on: January 05, 2005, 04:08:41 AM »


  Oh yeah high tech  

« Last Edit: January 05, 2005, 04:08:41 AM by tecker »
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tecker

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Re: interesting site
« Reply #3 on: January 05, 2005, 04:12:44 AM »
 I would imagin the market for that rascule would be some where around none
« Last Edit: January 05, 2005, 04:12:44 AM by tecker »
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JeroenH

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Re: interesting site
« Reply #4 on: January 05, 2005, 04:33:54 AM »
I would like to see one these in strong winds (from a distance ;-). I can see it snap easily. Even without abuse, that long axis keeps flexing when the thing rotates, I'm curious how long that would last.
« Last Edit: January 05, 2005, 04:33:54 AM by JeroenH »
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jacquesm

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Re: interesting site
« Reply #5 on: January 05, 2005, 07:08:36 AM »
Ok, I've discusses this selsam business for a bit with DanB and TomW, and the general conclusion seems to be that while mr. Selsam seems to be doing 'interesting' stuff it is in no way as groundbreaking as he claims.



The machine is fairly expensive for the amount of power that it produces, and mr. Selsam pulls a presentation trick in using rotor diameter as the comparision metric all the time where he should be using swept area. His machine is the equivalent of an 18.4' 3 blader 2*sqrt((3.14 * 3.5 * 3.5) * 7), which should comfortably be able to produce the 3 KW or so that the machine would produce when rated at about 25 mph (which is a high wind to rate such a machine in).



This would make mr. Selsams design not so hot, and this, combined with his attitude problems (which I only have as hearsay, but which his site seems to confirm) seem to be detrimental to the factual evaulation of his designs...



« Last Edit: January 05, 2005, 07:08:36 AM by jacquesm »
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jacquesm

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Re: interesting site
« Reply #6 on: January 05, 2005, 07:12:47 AM »
oops, correct that formula, I forgot to divide by 'pi'...



it's 2*(sqrt((3.14*3.5*3.5*7)/3.14), and since you both multiply and divide by 3.14 you can further reduce it to 2*(sqrt(3.5*3.5*7)).



this leads to a nice multiple rotor comparision formula, 2*(sqrt((d/2)*(d/2)*n) where d = the rotor diameter for one rotor and n the number of rotors...

« Last Edit: January 05, 2005, 07:12:47 AM by jacquesm »
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rotornuts

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Re: interesting site
« Reply #7 on: January 06, 2005, 10:40:55 PM »
I stumbled across this think by accident a while back and was intruiged for a moment till I realized the blades were seven footers. If they were something like 36" I'd be Impressed but as is it seems a waste of about four blades for the power output that's conveniently corrected to sea level. Still I give him credit for trying. I think the next most usefull thing to do would be to strap it to the roof of a truck and do some destructive testing, just for fun!!!
« Last Edit: January 06, 2005, 10:40:55 PM by rotornuts »
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