solar chimney turbine?

[Kwazai]

does nayone out there have any links for low speed drag foils- preferably flexible(parafoil kite type).  

[Kwazai]

here's a pic

[DBGenerator]

Your saying to use heat to turn a wheel to turn a generator??  I'm very interested.  I thought about that.  Problem is that you have to keep the generator far enough away from the heat so you don't cook it.

Something like that on a small scale would be great when camping.

[Kwazai]

I have been trying to figure out how to get some power out of a short solar chimney. which means among other things- low speed air flow-which means drag type turbines like a savonius. I posted a short solar chimney topic-looking for confirmation of theory more than anything else. with a 3ft dia. x 10ft tall chimney-possibly fed from a pvcpipe/poly sheet greenhouse- I should be able to get somehwere between 5 and 21 rpm at oz.in. torque. not really enough to generate electricity, but anytime the sun was out it would run. I live in NC and getting a steady wind of anykind means being about 65ft above the trees (more than a 100ft tower for a conventional turbine). It would take about a 30ft solar chimney to get the air velocity enough to be able to charge batteries. It also looks like the turbine for a 'short' solar chimney needs to be at the top of the chimney. The max. exit temperature would never get extremely high-so all of it could be plastics. I need more info on how drag kites are designed. this one would function a lot like a savonius rotor. The airflow would actually come from underneath the wheel, but being at the top of the chimney- if there were any wind it would also catch it-like a savonius. a 3x10 chimney should be able to water the greenhouse (relatively low powered pumping of water-ounces per minute....)

[Kwazai]

http://crestdl.lboro.ac.uk/support/dissertations/2001/hermancoetzee.pdf

I happen to think the guy above is a little overly optimistic in some of his assumptions about how a chimney works and that he wouldn't get the pressure drop at the base of a 'pipe' chimney he is wanting. that said- if he were to put the turbine at the top and use a chimney that looked more like a parabolic or hyperbolic cooling tower he should be able to. It has a lot of potential and I wish I were better at the math involved.

[Kwazai]

started putting one together over the weekend, will post progress pic soon.

L8r

Mike

[Kwazai]

pics of pieces-partially completed-have to add a collector. any comments?

[Kwazai]

tried to put it up in the wind a few weeks ago-will be another few weeks before I get back to it. with a 'wall' of plastic sheet it just about 'flew' without the sun being out.......(whole idea was wind genny without the wind-just the sun...) ..;-)..

L8r

Mike

[Kwazai]

got it partially put up-only place I had to put it was in the shade- will be testing it with a mosquito(kerosene) candle this weekend if the wind and rain don't tear it up in the meantime. no genny on it, just turbine. Will post pics if it spins.

[Kwazai]

not enough velocity flow in a short one to open the 'parafoil' turbine. I did however stick one on the fence that was lopsided and a recent storm had enough wind in it to make it spin (though erratically). I will be trying one at some point in the future when I can figure a more rigid attachment. the storm winds tore it up pretty good. just an update.

Mike

[joedupont]

if one lived on a south facing hill you could run some pe film up hundred of feet and maybe cover an acre.. some kind of  triangular shape would focus the

up draft into a high speed  jet  running through a turbine.  might work.

you could also super heat the air with mirrors..