Another VAWT Design

[Paul Lieb]

Hi all,

I am a draftsman that drew up something and need some real help evaluating its place in the world of wind turbines. I filed a provisional patnent in case I am onto something. The patent is for the connecting of 4 hinged blades into pairs with linkage. Any thoughts on it actually becoming a patent would also be appreciated. I have done a patent search and a youtube search and seen them all - I think!

This is the first one I drew up and it is a drag type. I have learned that they have their limits. Although I have hope that there might be variable draw generator that would increase load on the turbine to improve the efficiency thru higher winds speeds by keeping the blade tip speed below the wind speed. In other words the draw from generator would be controlled by a wind speed gage and make the turbine do more work to control the speed. The thing I thought was most important is reducing the negative drag as it comes up wind. I hope you can see how it works by studying my drawings.

http://i84.photobucket.com/albums/k38/BulBob/SAVONIUS.jpg

The second one I drew changes from a drag type (Savonius) to thrust type (Darrieus) automatically as the wind speed increases.

http://i84.photobucket.com/albums/k38/BulBob/Dual-VAWT.jpg

I am building a prototype at very small scale (using an erector set). I doubt that this scale will prove anything to anyone but I need to see if I can get it to run smooth. I am hoping someone has math skills to go with the little video I will try to make.

I also like fishing and have a fishing invention that is pretty cool so I thought since I invented something for fishermen maybe I could invent something for a green power. Man has been fishing a lot longer then he has been worrying about Green power! I added a page to my BulletBobber website that has info from my VAWT provisional patent.
http://www.bulletbobber.com/wipoin.html


Go Green Power,

Paul & Kathy Lieb
BulletBobber Enterprises
plieb@neo.rr.com

[Rob Beckers]

Hi Paul,

Welcome to Green Power Talk!
That is a neat idea you have there. It helps that you're a draftsman; the drawings are perfectly clear and I understand how it works.

The idea may be not be completely new (though yours may be a new way to do the job): I've seen VAWT designs that use articulated blades, changing the pitch of the blade vs. the shaft as it rotates, to keep the upwind drag down. Unfortunately I can't seem to find a good source that shows the principle. Thinking that Paul Gipe might have it in his book I've been perusing that, but nothing in there as far as I can tell. When I have some time I'll try a Web search.

-RoB-

[Paul Lieb]

Maybe your missing the point.
It switches from drag to lift as wind speed increases.
It will start at a low speed using drag.
During this time the blades will pivot in and out.
As the wind speeds up the blades will swing less and less.
This will allow the blade tips to spin faster then wind speed.

The two basic types of VAWTs are Savonius and Darrieus.
Savonius is a drag type and my VAWT uses the blade swing to take maximum advantage of drag with minimum negative resistance.
Darrieus is a lift or thrust type and please note that the 2 Darrieus pictures show the blades at the same angle to the support arms.

[Stewart Corman]

Paul,
Read through your thread and I am a bit confused on what it is you are trying to accomplish.

I have seen many articulated designs over the years.
http://www.ecowindenergy.com/rotor.html
http://www.watchtv.net/~rburmeister/Randys%20VSWindmill.html

increase load on the turbine to improve the efficiency thru higher winds speeds by keeping the blade tip speed below the wind speedthis contradicts aerodynamic principles

you are referring to TSR and for a drag machine it is TSR=1 and that is why they are so inefficient ...low RE# and corresponding low lift to drag ratio.
The "eggbeater" gets up to about TSR=3, but requires a driver motor to get up to speed to get the lift needed.

All the ones in California, to my knowledge, have been taken out of service

There are two primary physical detriments: they typically are mounted close to the ground, where wind is severly impacted by terrain and secondly, you only productively use 1/2 of the intercepted wind for power, the other half has to present some drag.

IMHO,the only concept that looks attractive to me is the "concentrator" design, whereby a fixed vane structure intercepts a large cross-section of wind and the moving parts within experience much higher WS than the environment is providing.
http://www.tmawind.com/

OT -- filing a patent is expensive and typically when a commercial venture is anticipated ...the US patent costs about $600 to file and another similar amount if accepted, then maintenance fees ...BUT, that is the inexpensive part ..to file internationally costs $4K and another few $K each for each country you file in, and then there are maintenance fee yearly. So if you just consider US, Canada, UK, and Austrailia ..you are looking at $15k

Stew Corman from sunny Endicott

[Paul Lieb]

I have 2 completely different theories for use of my linked pairs.

The first design needs an increased draw of power to keep its tip speed below wind speed so it is efficient at higher wind speeds. I don't know if that is possible. It takes some kind of variable draw generator. It does neutralize the negative by being flat and parallel to the wind on the upwind side and might even get some thrust on the upwind half.

The second design is self switching from drag to lift. The faster the the wind the less blade blade swing.

I would not write the patent. I know better then that - if it is a good idea and poorly writen patent your wasting yout time and will be in court all the time. I would expect to pay $20,000 for a US patent by thei time of award and $150,000 to cover the rest of the planet. The patent cost would be nothing compared to what it will take to compete with companies like GE and their monstosities.

I am hoping for a government grant and/or a company to step forward that wants to help a little guy with his dream. Or a big investor.

[Mark Ebert]

I'm not sure why you want to start it has drag based when the proper foils will start and save all the complications.Are you trying to bust through cog or something?

[Paul Lieb]

I'm not sure why you want to start it has drag based when the proper foils will start and save all the complications.Are you trying to bust through cog or something?

Excuse my bluntness but your question isn't a readable sentense.

I don't know what you mean by breaking thru Hanse Cog's sail ship design.
My total drag based design, the first one, does have big blades / sails.

If you are asking if I am trying to take maximum advantage of drag thru a big sail and then switch to a high RPM where the blade tip speed is faster then wind speed to take advantage of high wind speeds - yes - but only in the second design.

Ther are many blade / sail shapes to look consider.

http://i84.photobucket.com/albums/k38/BulBob/curvedblades.jpg

[Mark Ebert]

It will become more and more readable has you move on to the generation stage.
Good luck and have fun:)

[Rob Beckers]

Paul, the term "cogging" comes from alternators. Specifically permanent magnet alternators. It's said to be cogging when you have to apply a certain amount of force to start it rotating. When rotating it'll feel as if there are 'ridges and bumps' for lack of a better way to describe it. This is caused by the magnets preferring certain positions due to their interaction with the laminates. Since wind turbines (other than the drag devices) are stalled when they don't rotate, a cogging alternator makes it hard for the turbine to get started.

Hope this helps.

-RoB-

[Mark Ebert]

Nice explanation Rob:)