Vertical Axis Wind Turbine Built Like a Squirrel Cage Fan

also about how much power is possible (watts) from the afore mentioned vawt i understand it will be fraught with peril and horrible inefficient but just a good round about range

I'm sure many others will respond as I am doing now: please read the protocol for using this forum.

Protocol? Did I do something wrong?

WindGenMan, you're an asshole! Why don't you help the guy instead of chastizing him/her for something that they didn't even know? I won't be joining this forum and suggest others find another, more friendly place to ask their questions.

JK

It's been done, but the most efficient rotor shape is like a cage

of curved vertical wings. Pretty complex curves. Also pretty to look at.

Just FYI, I saw an interesting documentary, actually a series referred to as Planet Green on the Discovery Channel in which a patented design from a chap in Chicago that is now being implemented. His design, the Helyx, apparently operates well either vertically or horizontally, and is great for gathering energy from nearly random directions.

It's not my skill, but it interested me, so I share it with you.

http://www.metaefficient.com/renewable-power/rooftop-wind-turbines-ready-for-commercial-use.html

A friend of mine who owns a metal workshop in Gloucester, built one of these about 3 years ago. It was about 2m x 3m, with many vertical blades just like the fans you get in domestic heaters and on test, would rotate with the air flow from a desk fan. The main problem, as I remember it was with the actual electrics/generator part. This type of fan would require air to enter/exit at the top or bottom of the cage and might need another horizontal fan or helix on the vertical axis to help the exhausted air to escape cleanly. I suppose you could also use it as a self powered extractor fan to ventilate a building which would be doubly useful.

I once had an idea to mount a multi blade cage fan along the full length of my garage roof at the ridge. By careful design of the blade angles and inlet/exhaust slots it probably would generate a fair amount of electricity and be totally unobtrusive. You could even mount the rotating parts inside the roof angle with inlet and exhaust slots barely visible from the outside. Might be a bit noisy though!

I presume this principle is so obvious that it must have been tried and rejected by the wind fan fraternity?

that's very interesting now I wonder if you made a couple sets of fan blades the size of the inside diameter and installed them inside the turbine. As it rotates it might vent itself

This question has been already discussed in extenso try previous threads on CR4.

There is a proverb which says other mothers did also have clever children.

1) Ignore the folks who don't wish to see this discussed any longer, or complain about protocol. They don't ADD anything to the discussion, and they don't help YOU, nor any of the rest of us, to either learn something, teach something, or see a new way to look at what we already know.

2) Keep up the thinking, as you've already given me some useful information, and helped me out.

3) Savonias rotors (not sure of the spelling, may be also Savonius), which are not thought too highly of by the "if it isn't near 100% efficient it isn't useful, so buy instead of build it" crowd, are a good design for the self builder, particularly if he or she doesn't have a machine shop, and exceptional machinging skills, looks similar in cross-section to a squirrel cage fan, but with far fewer blades. I think with a Savonius (I'll use this spelling. If anyone knows better, please correct me), that the overlapping curve at the axis, which results in a scavenging effect, would be shadowed by the existence of more blades, so two is probably optimum. I think I read once about a three blade Savonius, but that seems to cause a balance problem.

I've seen a couple of governor mechanisms for Savonius rotors, but their purpose was not to keep the generator off-line below a certain output, but to slow the rotor in too-high winds.

Beyond all that, I like the "turbine as ridgepole" design, as I think it would make good use of a necessary part of the building, though I think I'd put it just below the ridgepole, inside the truss-cage, so as not to weaken the upper strength member of the building. It doesn't snow much here, but even a little could cause problems with code and insurance, in the event of a structure failure.

I also think I'd make it a "roll" or set of turbines, to shorten the axle, for simplicity in getting it to run true. Of course, that would necessitate more bearing sets, increasing maintenance complexity.

Ah, well, trade-offs abound!!

Micah

I was going to use the outer wind deflector tower to support the top of the turbine like a superstructure I think. I also wanted to use semi tractor trailer axles for the center shaft (I'm a truck driver) because they have tapered roll bearings rated at 8500# each side or 17,000# per axle as the legal limit or higher with permit but can far far exceed that number. Could also be made to be modular just stack more on top ( has a nice 10 lug bolt pattern)

Sounds like a lot of weight in your structure. I thought about doing the whole thing with 55 gal metal drums only if I couldn't get my hands on the more modern version, the 55 gal (or other sizes, a great variety!) fiberglass drums. They cut easily with a jigsaw or circular saw (maybe even a box knife), weigh very little, are cheap and abundant in some places. In fact, it occurs to me that I might even be able to do the job with pieces cut out of 5 gallon "spackle" buckets (their are a lot of uses other than spackle, but that's a common one around here. Lot of home construction going on!). Using them, I could do the whole job nearly free. Find bearings out of some old electric motors, and have even more of them available for even lower overall prices.

I like the 10-bolt hubs as stackable idea, but that DOES add up to a lot of weight.

And I suspect that your answer, and the one following, were tongue in cheek, if not downright sarcastic, but I still chose to answer them as serious, since they serve my purpose.

Micahd

Sorry. Those "modern" drums aren't fiberglass. They're polypropylene, or something like it. Much more flexible, lighter, easier to cut, no messy fibers in your skin, all the good stuff, none of the bad (unless you count the fact that they ARE injection moldable plastics, and use petroleum, and generate carbon counts, and ...). But, cheap, light, flexible, available? All good stuff in my book.

Hi, this is PentaPower and it is wonderful to have more people who think the same as myself. I started a thread not long ago, just trying to get some answers as to find how to obtain the torque on the shaft of my turbine. Some people are interested in change, but so many cannot embrace the thoughts of our technological advances. I got some help and will soon have the numbers that I need to carry on. Visit my newly started site www.pentapowerturbines.com which I will soon be adding to. We can all get the most efficient turbines by learning from each other. The more minds together, the quicker we can advance. Thanks. PentaPower.

www.Pacwind.net they are building these now. Jay Leno has one installed on his car garage. They fan curve is much greater on theses which enables them to operate with out a wind speed limit and also they start in much lower wind speed/ wind density. And their design allows a lot smaller foot print and they are stackable to obtain more power from the same space.

Thanks. Since I would be building mine from readily available surplus objects (It looks like I could probably get at lest two, and maybe three, blade sets out of a single 55 gallon, or so, barrel), it looks like a really useful design. I don't like the lack of an upper side-thrust capable bearing, although I assume there IS a bearing in the upper part of what appears to be the generator rotor housing (the bowl-shaped, or truncated funnel shape, at the top), so I would probably design for a through-shaft axle, allowing me to move the side-loads up higher, and thus avoid any canitlever-ing effect due to the thrust of the turbine pushing off-axis in a wind. I'm pretty sure they make theirs with the lightest materials they can feasibly design in, to avoid that very affect, and allow for a much lighter, and thus probably more reliable, bearing assembly.

I notice they state that it is completely scalable. I wonder how well it scales DOWN, since most people's idea of scalability is UP, for more power output. I couldn't use, and wouldn't want to build, a multi-Megawatt, multi-hundred foot high and wide version of it. Rather, I'd want to use something with a turbine swept circumference of between 5 and 10 feet, and not much more than 20 feet tall, overall. I realize this would limit the available wind pressures to whatever is available at ground level (at least I could put it on a hill, anyway!) and would thus limit my available power, but it would put the whole project in a "doable" size, and make maintenance an approachable answer.

I like it. It definitely seems to improve on the Savonius rotor's "overlapping vanes" idea. I'll have to try this one out.

Micahd

I love the 55 gallon drum concept for a cage. I am wondering what type of generator you will be using? how will you be connecting to the "fan" and what type of power controller . Just asking

I'm thinking more in line with floating an automotive alternator across a battery bank to a power inverter, using a charge controller module. The total affect would be something sized to a home/small workshop, with any excess power possibly being sold back to the utility (I have more thinking to do on that, and need more information before attempting it). But for now, for testing purposes, I'd use this as an opportunity to teach/learn with some middle and high school students I tutor in Science Fair competition. We could all learn together, document what we learn, and the kids could make use of their own work and ideas as the basis for some good projects.

As far as power connection, I really like the idea of non-newtonian clutches, but since they work to deliver more power at higher "slip angles" (read, in this case, higher speeds) and the requirement might be to limit overall rotational speeds (we had some REALLY severe storms here last night, and in the part of Pennsylvania, that I work in), any clutching system would have to be over-ridden by a governor system, also. Still working on that.

What I like about the non-newtonian fluid idea is that it works like a soft-stall torque converter in a car, and can be made lightweight, small circumference, thus limiting the centrifugal force load added to the system. And at low speeds, not much gets coupled across, so that turbine is free-wheeling up to an adjustable speed, where it then progressively couples power to the drive mechanism in greater amounts, as it generates greater amounts of power. There is an adjustable band in the range where it delivers only part of its available power, and the adjustment range is both in set-points and in width of the range. Above the upper point it couples over all the available power.

Micahd

Its been done by many companies who produce large & small versions. Try clicking on this link for a good looking proven design:-

Savonius Wind Turbones

Thanks, Andy. I like that design, but suspect that it might put a real tax on my ability to cut the blades with any kind of balance. On the other hand, I've long thought that a design like this could result in a greater ability to start at very low speeds, and thus extend the usable wind speed range much lower.

I'd have to try it out (Or get one of the kids to try it, if I can find one who can handle the art/cutting better than I do).

Micahd

If you have ever seen a cylinder mower blade sharpened, you will understand exactly how to get the blades done well......Just on a bigger scale.....!!

I hate the Internet sometimes. No not sarcastic!!! I came here for help and advice. I don't see how you thought that. I just want to know how well ( and if) my ideas will work.

The ideas of yours are not new, the turbines do work, in fact Arabs in North Africa have been using such wind turbines for the best part of 2000 years or more......!!!!

What were you looking for? We have told you that such designs work, we have had several CR4 discussions over the last year or so on this subject as well....you could have searched them out and read up.....

Perhaps you felt we should have applauded you? Or what??????

WOW!!!!! 2000 years that's awesome!! I had no idea arabs had the means to compress air and use it linear pneumatic cylinders. Geewhiz I'm way out of my league here. Oh by the way do you have a link to one so I can see it?

I wonder did they use reeds and papaya for the cylinders? And an elephant for the compressor that was a long time ago................. Now, that is sarcasm

....of the very worse sort.

You should try not to use sarcasm as humor, it displays a convoluted mind.....

.....sarcasm must be used sparingly to have the correct effect!!

Not like a Yank with a steak and a ketchup Bottle!!

They use them to power simple water mills to get water out of the ground/desert floor, National Geographic did an excellent program about this at least 10 years ago (when we got it!!)

You really are aptly named!!!

I apologize. I have run into so many who were sarcastic, or caustic, I let my worst nature run away with me. I appreciate the efforts of anyone to spread knowledge around, and find it refreshing even to rehash what's already been said (see Andy Germany's next comment #20).

Please accept my apologies. I seem to cause myself too many opportunities to ask that, and will work hard to curb my tongue.

Micahd

Now don`t run away with yourself, I was only trying to find out what it was you were looking for as I STILL haven't a real clue....

If it is any consolation, some of us have also "got on the wrong train to London" so to say.....its not a crime!! Its human!!

Back up, take a deep breath and try to write something that will allow us to help you further......no more, no less....

Have a great day in spite of me!

awwww come on it was just a little bit funny though right? Ok I'll try to draw some sort of rough sketch tonight (serious no sarcasm) but I'm no artist. By the way I was wondering if someone could help me out. I am having a difficult time figuring out the amount of power this rotor "could" produce. I am just not able to understand the algebra, conversions, # of blades, if its different for a savonius ( mine will be) vs hawt. I won't ask someone to calculate it but could somebody maybe explain it to me? I have been all over the net and its too technical. It would be great if someone could explain it in simpler terms or even like as to a child LOL. So thank you in advance if you wish to impart or share some knowledge.

The first VAWT were built in 3000 BC by Egyptians to grind grain. They used a cloth sail as blades, copying those on their sailboats. Variations on the material were used over the next several centuries, but the VAWT configuration, as well as the drag profile, stayed the same. Europeans adopted the technology but eventually discovered that if the blades were flipped horizontally, the machine became more efficient at extracting energy from the wind. In addition, they discovered that if they flattened the sides of the blades facing the wind and rounded the leading edge while adding a slight curve to the lee side of the blades, they became even more efficient. Thus the lift profile was invented. As you know, this same configuration was later used on airplane wings to help them fly.

The vertical axis generators now on the market are merely a reinvention of the old Egyptian wind mill. Even with the lift profile used on VAWT blades, the machines are still 50% less efficient than those using the horizontal axis configuration. Shielding the drag side of the blades may reduce drag--although not much--but does nothing to increase the area capturing the wind energy. The magic formula for designing blades is: P=½ρAV³, where "P" is the power extracted from the wind, "ρ" is the air density, "A" is the area swept and "V" the wind speed. Simple physical laws that cannot magically be broken, even through wishful thinking. If you've any questions about the above, look at the highly competitive utility scale market and identify one manufacturer who is using the VAWT design. The engineers in those firms are no idiots. They get paid big money to design the best, most affordable machines. Unfortunately, companies such as Pacwind use very clever marketing to sell their inferior machines to people such as Jay Leno, who can afford them but do not understand the basic laws of physics. The VAWT machines look very sexy compared to most HAWT, this I'll admit. My concern is: how are companies such as Pacwind affecting the credibility of the small wind industry? Unfortunately, very negatively. In California, small wind, like residential solar, will be critical in bridging the ever increasing gap between supply and demand of electricity, which is projected to be a full 20% by 2017. Unfortunately, due to its high public profile, enormous cost and poor efficiency VAWTs will only generate a poor image to the small wind industry.

My two cents worth.

The technical evidence definitely shows that for performance HAWT is superior to VAWT, but most people would prefer not to have a horizontal bladed fan on a pole next to their property - looks 'orrible especially in an urban area. I think this is why a lot of people like the idea of the vertical axis unit.

At the risk of upsetting contributors to this 'mature' discussion subject has anyone designed a ducted fan system? This would collect the passing wind/air flow using a moveable cowl, duct it through a HAWT and exit through another fixed vent. By using a large cowl you would get a much greater air flow in the duct allowing for a bigger or multiple HAWT. Because the HAWT would be in a fixed position it should be easier to control the speed by 'spilling' air from the duct using pressure vents, etc. If the duct and HAWT was mounted inside the building in the unused space under the ridge all you would see from the outside would be a modified line of ridge tiles or a free moving cowl which could be any shape, (you could even disguise it as a weather vane, I suppose!).

On aircraft, ships and missiles designers have found ways to feed air to turbines through ducts bent in all directions and the systems are very efficient - why not use the same technology to produce a domestic power generation system - you might even be able to utilise HVAC ducting and technology with a HAWT in place of the extractor fan. Another benefit would be ease of access to the HAWT for maintenance.

Those engineers old enough to have been working on aircraft with either propellers OR jet engines will remember the excitement when they combined the two into a turbo-prop design. Much more power, much safer and nicer to be around - technology keeps moving and improving.

http://www.youtube.com/watch?v=f-ixAoelEjM

I have +/- 650watt at 11.4 m/sec wind with 192cm diameter and 96cm hight the blades is 84cm large. haegeman_l@skynet.be

Interesting, Thanks for the demonstration. Looks very scalable.

And welcome to CR4.

Brad

please don't misunderstand me I know that I have NOT reinvented the vawt or even improved upon it nor have I broken any new ground in the area of power generation (as I'm so often reminded). I have done absolutly nothing new or even Interesting I have done enough research to know the efficiency differences between the types of turbines. That being said there are reasons in this world why a person would even consider using (gasp!!) a VAWT ( its not a dirty word) just a few would be the ability to build one of varying complexity by yourself. not everybody is an extremly smart genius expert educated knowing diehard person such as yourself. another reason would be guidewires not enough room all the time and before you say it I cannot afford an expensive monopole setup, but I'm sure you can. Another reason (something important in my mind) is the ability to experiment and use other means do drive MY generator head ( like air, hydraulic, spinning it or whatever) which is useless until I can get it to turn. There many reasons why some people won't, can't, or don't have the " sporty" turbine (hawt) and are going a route more suited to their situations. Have a nice day

hmmmm sounds pretty interesting I imagine it would self direct itself into the wind right? Do you think you could draw a pic of it? And I would like to sincerly thank EVERYBODY for responding (even if I didn't like some of what was said) to my post it has been very useful.

FIRST - I'm not an engineer of any type.

But, I've been thinking about the same thing. We have 2-sources of air movement in/outside our homes, Furnace fan the the Air Conditioner fan outside.

Wouldn't it be nice if we could acutally combine the furnace fan motor with a wind turbine to let the motor start up and when the airflow was sufficient get the turbine to generate the electricity to keep the fan going without the fan motor running.

Guess that proves I don't know anything about engineering.

Don't know how we could use the A/C fan unless that "Windbelt" invention could be modified to fit on top of the fan.

maybe you could incorporate some sort of free wheeling design (like on a bicycle) so the system would work like normal until the turbine had enough speed/power to take over?

Have to have a source of windflow from "outside of the loop" to avoid trying to do perpetual motion. So, you'd need a source of environmental wind flow to make it happen, such as a strong wind over the house, in a sufficient speed/direction to cause the turbine to spin, either by positive pressure (trying to drive air into the house) or negative pressure (trying to suck air out of the house), either of which could only be optimized by the turbine being squarely in the only, or at least, major, path of airflow at one end of the chain (you'd also have to have a place to source/exhaust, as necessary, the air leaving, or entering the house, respectively. Think of it as a wind pipe with the turbine at one end, and recognize that if there is a leak in the pipe, flow is not optimized).

All that said, and if you could meet these requirements, you could make the "fan starts till the turbine takes over as a power source, powering the fan" idea work, only if you could reach a power in (wind) conversion to drive force for the fan (belt, generator, direct driveshaft, or what have you) efficiency which exceeded the efficiency of the wind turbine's use of its drive air.

There, I falter. Anybody know the kind of efficiency numbers we're talking about, reasonably, and the calculations for losses in various drive conversion methods?

Micah