for vawt people

[shagy]

i am new at this and at some point in time i would like to build a wind turbin. I have read that a vawt will spin at a lower rpm that a hawt does. My question is , if one could take two vawts of the same size and stacked them on top of each other spinning in opposit directions, atatch the rotor to one part and the stater to the other part? would this work and if it does wouldn't it double the rpms

[vawtman]

Hi Shagy

 The problem is you cant spin the stator without using brushes and a commutator.Would be cool though

[shagy]

sorry i ment to ad that about the brushes and it also seams that the more i read the less I know

[vawtman]

I had the same idea when i first started it was a shaft within a shaft and was all exited until my dad mentioned "how would you get the power from the stator":<(oops

 Where theres a will theres a way.They would look cool.

[sk windpirate]

That system would work and quite well I expect. But it would that a lot of work.

why not If make a Gennerator to accomidate the lower speed VAWT? You would be building some kind alternator anyway. A 1/2hp induction motor convertion with decent magnets will reach cutin speed at about 80 To 100rpm's.

[electrondady1]

it might be worth an experiment or two if you can monitor the power required accurately.

the fundamental thing is there is only a certain amount of power in a given swept area.

you are dividing the swept area into two halves and running it in opposite directions so  the mags are passing the coils  at twice the speed .

but what happens when you put the Geni under load?

I'm thinking the geni might slow down twice as much .

if your willing to belt/ gear drive the alternator you can make up for the slow rotational speed  

or build an alt with a larger dia.

it's an interesting idea.

why not do a working model first?  

[shagy]

it was just a thought that i had. Kinda sounds like this would be more of a toy than a working turbin

[electrondady1]

seems like a worth while line of exp to me shagy .

don't give up on it too fast.

if you can make it work everyone will jump on board.

[commanda]

I've been holding off on this idea for quite a while. This might be an opportune time to raise it for comment.

The stator (coils) is stationary. The top magnet rotor is attached to the upper vawt thingy, and spins; lets say clockwise.

The lower magnet rotor is attached to the lower vawt thingy, and spins the other way, say counterclockwise.

So tell me why it won't work. There must be a reason, otherwise it would've been done long before now.

Amanda

[shagy]

I understand how you determine the power of the swept area for a hawt but is the swept area for a vawt different. I also know that there are several differnt types of vawts does each one have a different swept area for the same size

[vawtman]

Hi Commanda

 Had the same thoughts,not a good idea has i found out.

 http://www.fieldlines.com/story/2006/10/10/232638/13

[vawtman]

Heres a calculator Wind4reg posted awhile back.Fun to play with.

http://users.xplornet.com/~rmanzer/windmill/rotor_calculator.html

[electrondady1]

commanda, i think we are talking about two different things here.

your proposing a stationary stator with two counter rotating mag disks.

i can see problems with with getting the poles to sync up .

what shagy is suggesting(i assume) is a conventional dual rotor but with the stator counter rotating .

the frequency would be double.

four bearings would be required as well as a set of brushes

 

[elvin1949]

shagy

 It is a very doable design.

A lot of hawt's use slip ring's so you can find them.

 On a vertical wind gennie you put the mag's on the bottom of the top set of blades and the stator

on the top of the bottom set of blades.

 Put your rectifers INSIDE the bottom rotor

and the slip rings at the bottom of the bottom rotor.

 I ain't very good with word's SOOoo hope

you get the idea.

later

Elvin