Vertical Wind Turbine

I'm still working on why a chain is a good idea. is it suppose to accommodate movement? you have less losses if you go direct, less moving parts to fail, less maint.

Because the professor assigned him the chain drive one.

I agree totally, however, the question then remains, how does he prevent the blades turning in a gale force wind? Does he then add additional heavy duty breaking calipers, an electrical locking pin through the hub or is there another mechanism utilised? A chain is not going to prevent the blade spinning and setting the nacelle alight or the blade spinning out of control.

Just a thought in his process that needs to be considered. Bigger chain, more drag, more friction, less output and more safety hassles.

A gear box adds drag but adds resistance when the blade is locked out due to high winds and there is one rather huge disc brake and several calipers stopping the blade turning in high winds, and it still can spin, even with feathered blades.

If it was a good feature, many nacelle manufacturers would be saving money and using a chain. It's fine on small units with small diameter blades and short height vertical type blades. Now he has to calculate stresses on drive chains? Perhaps his professor should advise more clearly that these are for home use and not commercial use. But, sincerely, good luck. Let me know how it goes.

For a vertical axis wind turbine, the tip speed is never higher than incident wind speed, and is usually a close approximation to the actual wind speed. Having this in mind, why is it necessary to brake the turbine at all? Let it roll freely, or at some maximal load, with a throwout mechanism for the idler wheel? This is the equivalent of a lossy, slipping system.

Next question: will this produce enough heat to cause a fire on the rubber drive wheel, or the driven generator wheel through slippage? Maybe indeed, it would be best to completely disengage the driven wheel at 95% of top load rating. This can be done using an electronic latch control, that locks out the device until things settle down just a bit.

Why use a gear or chain drive ?

Rather produce DC and convert to AC.

SIR I DO NOT UNDERSTAND WHAT YOU ARE SAYING PLEASE ELABORATE IE

What is the expected power output of your VAWT??????????

I don't think you're ready for this. With no idea of how to proceed, it will be difficult to succeed.


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See #13.

I agree with you (for once). He could be a lot better off installing a hard rubber wheel on the hub of the rotor at the bottom, and apply a much smaller friction wheel (also rubber?) to run against this and drive the generator. Besides that, who does not like the smell of burning rubber?

Bad news for me ,,, i am not authorized to do this project as this got no innovation . All my work is wasted . But here's a hope now this time i will need your help with thermoacoustic refrigerator , See to be very honest i don't get very brilliant faculty here, so i can't hope for any help from those kittens. i have searched google and just wondering if it is possible to make it on university level .. how and where should i look for resources

The Hittites invented the wheel, Archimedes the screw. several hundred years ago and here we are inventing the same thing yet again. The gear box was used simply because it was tested against belts, chain drives and direct prop shafts. Are you sure you want to invent the wheel again? Perhaps change your thesis or adhere to the simple principle of 'KISS'. It does work. And use the internet to do research. It is an amazing technology that usually works fine.

Dump the idea of a chain and use a cog belt drive if you must. It should be enclosed for protection.

I like the efficiency of chains but in the case of a vertical windmill, the orientation of the chain will cause additional wear because the catenary of the chain will want to misalign the chain on the sprockets unless held at higher tension and keeping the unsupported lengths of chain to a minimum. You will find most chain drive systems have their sprockets in a vertical orientation unless the distance between the sprockets is very short.

On my motorcycles, I can usually get about 20,000 street miles out of a quality O-ring chain that is exposed to the weather, and probably not lubricated as often as I should. 20,000 miles is less than 500 hours of operation. The three or four row primary drive chain on my dad's 1978 Saab 99 Turbo that is bathed in oil survived up to just a bit over 200,000 miles. He timed it just right. He was driving it to the scrap yard in the nineties when it threw the chain. Too many other niggling problems to keep the car going. Original Garrett turbo by the way. He was less than two miles away. The yard came out and towed him in the last bit of distance. (It's like when your cat knows you're going to the vet. Del can probably elaborate more on this.)

Even at 200,000 miles, which sounds like a lot, equates to about 4,500 hours of operation or one half a year. Even if we assumed the RPM was one-tenth of a car, that is only 5 years of operation with a well designed, supported, and exceptionally well lubricated chain.

To make a short story long, I have a hard time recommending a chain in this application, UNLESS you are using chain drives for DEVELOPMENT only because of a chain drive's low-cost, and ease of changing 'gear ratios' to determine the best operating set-up.

Good luck with your quest.

(P.S. Why is catenary NOT in the CR4 spell check dictionary?? Of all things . . . )

The book "The Boy Who Harnessed the Wind" by William Kamkwamba might give you some inspiration.

THANKSS, I WILL TRY TO SEARCH THIS ONE ONE NET

HOW ABOUT , USING A CHAIN DRIVE WITH A GEAR BOX AND THEN ITS SHAFT TO GENERATOR

High power losses....how about direct driving magnets....passing coils mounted around the circumference...coils tied to provide polyphase output...this output to polyphase diode bridge...dc out to buck/boost inverter...storage...storage to ac inverter

I AM SORRY GUYS I THINK THIS WAS NOT A VERY GOOD IDEA WHEN IT COMES TO YOUR FINAL YEAR PROJECT . THAT'S WHY MY FACULTY THREW MY PROJECT IDEA AND MY PRESENTATION OUT OF THE WINDOW AND I AM IN SHOCK ,,,,,, I WOULD LIKE YOU TO TELL ME SOME MORE FINAL YEAR PROJECT IDEAS RELATED TO MANUFACTURING , ACTUALLY I WAS COLLECTING DATA REGARDING VAWT'S FOR ABOUT 2 YEARS AND NOW ALL CRAP .. YOU ALL ARE VERY MUCH WELCOMED IF WANT TO HELP ME WITH THIS ...

This was known in your first posting, but good for you for admitting the truth.

Best advice, don't reinvent the wheel.

Be original.

Do your research properly and thoroughly.

When you have done that contact me and i will help you and I am sure many others will too.

You don't believe i have searched 100's of project but i don't understand how to make them . most of 'em are research papers.

What is your new project to deal with?

What are you aiming to achieve with the new project?

How much time do you have to hand in your project?

Are you intending to build it or theorise the idea?

Give me/us details and we could help you

How about thermoacoustic refrigerator. I have heard about this technology , can you help me with this one . I mean ,, look i don't get that much talented faculty who i think can hell tell me about this , i have searched google but how can i make it in a small level or you know better for a university level . Man i can not concentrated on any other project as u know what happened with my idea .

Do your searches on: (1) stirling engine as cryocooler, (2) thermoacoustic heat engine (entry on wikipedia), this suggests a quite high acoustic intensity may be necessary.(3) consider magneto-caloric effect cooling, and (4) electro-caloric effect cooling. Perhaps one of these will be within your range of experimental apparatus.

Good luck.

If you wanna use excitation, like that in those commercial turbines or in car generators, you would need to step up your wind rotor speed but, why not use belt drive instead, if you must use a gear transmission. Chain is the worst drive you could use! Direct drive is the way to go, especially if you use Permanent Magnets.

Also, try to use magnetic thrust bearing to eliminate or reduce wear and tear on the mechanical one..!