so from your description your son has thought of a Chimney

with a centrifical fan on the top ?

http://www.google.co.uk/search?q=updraft+through+chimney&sourceid=ie7&rls=com.microsoft:en-gb:IE-SearchBox&ie=&oe=&rlz=1I7GGLT_en&redir_esc=&ei=5yKfTOeBCNm5jAeu1I3CDQ

he is 21 and doesnt have access to the internet ??

Turbines

http://www.google.co.uk/search?q=vertical+turbine&sourceid=ie7&rls=com.microsoft:en-gb:IE-SearchBox&ie=&oe=&rlz=1I7GGLT_en&redir_esc=&ei=vSKfTNiLJ5a6jAeHzLi0DQ

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You give yourself way too much credit calling those 'links'. They are Google searches ... non-informative and a waste of time. If you have nothing of personal or professional experience, or any other insight of your own, they why bother on this topic.

First let me say i'm sorry for coming off like a fool ... lets start over ... maybe we will both learn something.

Consider a horizontal axis wind turbine (or rotor) exposed to prevailing wind, geared to a shaft with a second perpendicular rotor located inside the top portion of a vertical tube (this will cause air movement in the tube) ... shaft also connects to a compressor located inside tube directly or by a belt (a belt would be great to change the ratio but will try direct first unless opinions suggest belt is a no brainer) ... compressor & large volume thin tank (tube in a tube) that receives compressed air, thus gets hotter pv=nrt. .... therefore, heat will be generated inside the tube ... additionally hot air can be introduced via a combustion process (incineration of waste products).

I can use less efficient components in the build and translate the loses to increase input ... In other words given a prevailing wind, I can increase the wind pressure by the amount I can show, in theory, that a different component would provide in efficiency. The build has to show how the system works and the paper can show how, if different components were used, that the desired output is achievable. Hopefully I will get close enough so that the corrected wind pressure doesn't blow the whole thing apart.

Ideas ...

Vane type compressor (TVS type looks promising and have that data) but will use components from a refrigerator (don't know how that will work out just yet) unless someone can point me in a different direction.

Turbines made via balsa (or fiberglass rods) and film (skin) - trying to keep mass low -but would a flywheel be of benefit? If so, the mass of turbines would not need to be made so light (or weak) and can just use mass of turbines instead of a flywheel? Design of perpendicular rotor considering it will act as a suction type device when prevailing winds are good (load vector down) and propulsion (load vector up) when combustion process is in use? ... Would 10 degree at the hub and 5 at the tip still apply? hopefully i can get a Cp of .25 -.3 ... and on paper .34999 :o)

Cylinders of different diameter PVC pipe sealed to make a 'tank' - would a higher conductive material, aluminum or copper, be better? Seems like it would - but would a less conductive material act as a thermal battery (slower released heat inside tube) to help drive turbine during periods of slack wind? Size of tank to store pressure for use in times of slack wind pressure ... how big is too big or too small. {We are testing that now.} The tank is what I consider a 'storage' component so the bigger the better is my opinion ... this tank may have various inlets through it to draw additional air to the center tube via venturi principle.

Heat input ... I have design and data for the incinerator via US Navy. Given that it is mentioned that only waste products may be used in any combustion process ... I'll probably need one. I'll get the wind pressure profile today (i suspect a weilbull distribution). It would be used when the prevailing wind pressure is not sufficient to meet demand (which is to be constant). Inlet entry of exhaust into the cylinder ... I suspect inlet coming in at the bottom would be most efficient ... but it would heat the pressure storage tank or does it really make a difference. The lower the inlet the lower the exit temp at turbines and possible belt drive given a sufficient additional venturi inlets ... so material selection to withstand temperatures eased for turbines is a thought. The incinerator exhaust will heat the 'tank' ... will i be able to cool the exhaust via venturi inlets? What if I angle the venturi inlets to create a vortex more or less confining the hot stream to the the center and the drawn in air at the sides of the tank ... would that work ... or will that mess things up and wind-up making a Ranque-Hilsch vortex tube ... would i need a stator type arrangement at the top to prevent that situation from occurring ... would a stator be a benefit when the incinerator was not in use ... seems like it would be a good idea from the get go ... based of jet boat pump design ... but really don't know. What about a filter ... if I directly exhaust the incinerator into the tube should I worry about that?

things I haven't spent much time thinking about ... yet:

instead of the perpendicular rotor ... an inline rotor inside an elbow arrangement.

Furling system ... good furling system for this set up anyone?

Stirling engine in conjunction with exhaust from incinerator.

Turbo charger type set up on expansion valve to aid efficiency? ... just throwing it out there ... have not put much thought into it yet.

Drawing air through a length of copper pipe placed underground thinking cooler denser 'charge' of air.

roof design ... I thought I read somewhere that the turbine should be 10m above anything ... but is that for turbulence problems for generating electric charge via a generator or just in general ... prevailing wind is from west to east due to topography and vegetation.

plantings to form a tall 'hedge' to aid in directing or compressing prevailing wind to intake of the tube.

----------------------------- I'd be just as happy if someone points out why any of these would be bad ideas so I don't waste time on them. Obviously good ideas are better :o)

Anything else to consider?

optimum height for wind turbines.

You mentioned somthing about 10metres

http://www.google.co.uk/search?q=optimum+height+for+wind+turbines&sourceid=ie7&rls=com.microsoft:en-gb:IE-SearchBox&ie=&oe=&rlz=1I7GGLT_en&redir_esc=&ei=EzynTJLcLoqQjAeKyKTuDA

"I thought I read somewhere that the turbine should be 10m above anything ... but is that for turbulence problems for generating electric charge via a generator or just in general ... prevailing wind is from west to east due to topography and vegetation."

this i beleive is in relation to the following link which is about pillar mounted wind turbines.

i have not read the links, and provide them in casr you have not found them.

If they are of no use do not read further

i would also suggest you look at the suction a roof of a house provides, this information may be on one of the links i have already provided.

its the property of the chimney/or stack protruding above the roof to provide the stack with increased updraught, if all these where incorporated into one design it may work.

The purpose of this post was to assist you in learning how a chimney works,

this i thought would assist you in designing a working system.

as is the the solar illustration links i know your dad didn't mention solar, but when designing a new system i have always found in beneficial to fully understand all the variations of the subject.

all the work already undertaken on similar projects in fact anything that would help me to design a product.

so the purpose of the links was to stimulate your mind to see if there was anything else that perhaps you hadn't considered, and to show you all the systems that have been tried and tested.

This should enable you to at least make a working device without lots of experimenting.

you can thus learn from others failings.

there are after looking at the useless links i have provided a couple of ideas that spring to mind to improve on the basic idea, that incorporates some parts of all of the information contained in the links.

and once i have placed all the links in one place it saves me time because i have done all the finger work and all the links i will need to further the idea are now in one place, even if they are not usefully to you.

But as you've completely misunderstood the logic behind what i was trying to achieve.

sorry about some of the sarcastic bits but your complete misunderstanding of what i was trying to achieve was very disappointing

A wind turbine could be adapted to turn a refrigerant compressor. The evaporator could serve various cooling needs, and the condenser could do some heating duty.

Thank you for your time ... I see your idea as basically a miniaturize version of a HVAC ... which is great, because it can be easily adapted, and I can possibly get some old fridges from a junk yard. I could get some green bonus points!

I hope to be able to cool a 200x200cm area such as a king size bed. I hope to include a thermostat so that the excess can be diverted, or debt to call upon a boiler/incinerator to activate which would hopefully increase the cooling. The Paper is to show that micro climate control can save substantial nrg in certain situations like when we go to sleep.

Do you think it would be worth it to put the condensing unit inside the mentioned cylinder to aid in updraft? Or, could better efficiency be gained by using the condenser to power a sterling engine to help run the compressor/condenser (some coils would still enter the cylinder?) Would there be enough heat there between the condenser and maybe the internal air column of the cylinder? A different way? Thoughts?

I can estimate the torque of a turbine at a given wind speed, translate that to the condenser and use the pressure change minus work to get the heat. What I see as hard to estimate, is the effect of the air movement in the column (convection). If I put the cold side of the sterling inside the column at the columns lowest part ... setting the coils of the condenser in the column a bit higher? The Stirling to run a fan inside the column to aid airflow aid the compressor.

If I can get enough BTUs out of such a system to operate a cooling blanket, I can get cracking on this idea for my school project.

For school, I just have to do the math, but I can get a free exam drop, if we also turn in a working example, where we can set up the conditions within a set of maximum parameters (So roof design might help). It is my Friday class and this is the only class I can't skip the exam with an A average (unless project is a success). Thus I'd be able to go with my dad to Port Elizabeth when he goes the week before semester break. Otherwise, I'd say ta hell with it and wait till my junior year when I have to do it.

Any help appreciated. Sorry I gave the previous guy the finger for his effort. I should have just ignored it.

A Stirling cycle depends largely on temperature differential for any efficiency. This does not fit a wind turbine setup very well.

Generating electrical power from wind can run a compressor, but the controls will be somewhat complex and the losses significant. This more or less rules out the hermetic motor-compressor of a domestic fridge. However, an open compressor with a belt or gear drive could be run off a turbine, and could work at varying speeds.

There are still some obstacles. A compressor is very nearly a constant-torque device, whereas turbine torque varies as the square [?] of wind speed. Either some compromises will be required, or perhaps a variable-speed drive.

Before adding in combustion processes and energy recovery from them, I would start with a straightforward heat pump system as already outlined, and then consider augmenting it.

I thought about connecting the turbine to the compressor via a flexible shaft that is found on some electric weed eaters (though I have a concern it may melt) or perhaps just brazing it directly to the turbine shaft. Rotating mass considered, I'll have to make a trade off there I think. A 1/8 scale set up might be able to use the weaker weed eater part. If I braze it to the turbine, I'd have to come up with a way to protect it, if I go with an augmented combustion process (I am limited to burn waste products only ... trash grass leaves etc) ... putting the compressor as low as I can could get it out of the way of the augmented process.

I think that direct connecting to the turbine would require a large volume storage tank for the gas, so it can store excess pressure (hopefully) without exerting to much back pressure on the compressor. A check valve/ relief valve will probably need to be placed after the compressor. I could double wall the cylinder most of the length and make a rather large storage tank out of it. IE work off of a variable pressure in the tank rather than worrying about varying the compressor. Opinions? any better way?

use turbine to generate electricity which is the easiest option storage then could be in a battery then run compressor from electric motor.

this way the varible out put from the turbine would not be an issue.

also in extreme cases you could augment the stored power from solar panels or generators etc, it would be a more flexible approach giving you much more options.

Good help, I gave you the third GA, mainly for keeping a level head and continuing to try and help while someone asks for help and then gives you the finger. He and his son may not have known about Google or Wiki or if they did maybe they don't have access, there are 1000s of engineers around the world that don't have access to it due to gov't regulations. Rest assured when (and if) his son ever gets into the professional world, if he treats his coworkers to "the finger" after asking for help and getting what he thinks is no help at all, then he'll soon be unemployed. What goes around comes around.

Thanks

by the way looking at the design i have listed wouldnt it be better to place one large turbine at or near the top of the chimney where i would have thought the air would be moving faster and therefore more stored energy.

in the drawing the turbines are placed at the bottom but there the moving air would surely have very little energy ?

just a thought, perhaps a little experimentation would be in order ?

calculations that may be usefufull

http://www.engineeringtoolbox.com/natural-draught-ventilation-d_122.html

Peter.. I argued against the Australian solar wind turbine and I think my idea was instrumental in stopping the building of a very tall and wide one in the desert .. my reason in a nutshell was this.. to continuously project a very large volume of super heated air into the upper atmosphere was bad enough.. to do that with dust and other wind borne debris would be catastrophic you would not only be disrupting the jet stream but polluting it and changing the thermal balances..Strangly no one from the company that proposed it had considered those things... So they went back to the drawing board..or whatever their so called designers used..anyway no one has built one yet..and I hope now they never will

http://www.brighthub.com/environment/renewable-energy/articles/65014.aspx

Comparison of Solar Chimney and Heliostat Solar Power Tower Systems

Article by Harlan Bengtson (8,249 pts )
Edited & published by Haresh Khemani (26,714 pts ) on Feb 25, 2010

Two different types of power tower solar plant show great promise. One is the solar chimney power plant, that generates wind in a solar chimney to drive a turbine. In the other type, like Solar One and Solar Two, each heliostat in an array sends solar power to a central receiver on a tower.

Introduction

The terms 'solar power tower' or 'power tower solar plant' are used to refer to two quite different systems that both generate solar power electricity. Both systems use a rather tall tower, but other than that they are quite different.

One type, also called a solar chimney power plant, uses solar collectors to send heated air into a very tall solar chimney. The updraft thus generated, turns a large wind turbine in the chimney/tower to generate electricity.

The other type uses mirrored heliostats. Each heliostat in a large array reflects incoming solar energy to a receiver at the top of a centrally located tower. The heat generated by the reflected solar energy is used to generate steam that is used for Rankine cycle thermal generation of electricity. Solar One and Solar Two near Barstow, CA are examples of this type.

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