Building a wind turbine with Pivoting wings.

Hey Guys,

I am currently designing a H-Rotor Vertical Axis wind turbine that will have pivoting wings.
I am hoping that these will help me master the angle of attack.

I am wondering what efficiency I will be able to achieve using this system and what is the best angle of attack.

The wind turbine has specs. of 2m diameter by 2m blade height.

Regards,

James

Lift... Drag... Angle of attack... Reynolds number...
TOUGH question that has a lot of questions of its own! What kind of wind are you expecting? What airfoil design are you using? What kind of shaft loading are you expecting (in watts or otherwise)?

http://www.allstar.fiu.edu/AERO/lift_drag.htm
http://en.wikipedia.org/wiki/Reynolds_number

I think the variable angle of attack is a great idea. The only thing cooler would be a magical variable airfoil :)

Some basic stuff to keep in mind:
Increased angle of attack generally means increased lift and increased drag.

So.. increasing lift increases your "torque" and therefore makes low-wind startup better.
But it also increases drag which will slow down your rotations (lower RPM)

A variable angle of attack that was RPM defendant would be the best but Im not sure how this would be implemented (springs and centripetal force perhaps? Active electronics?)

This would allow your turbine to accept a variety of wind conditions and even stall itself out for maintenance or high-wind conditions.

Can you post some pics or drawings? Im very curious to see your design ideas.

Thanks

-George

My Website: www.GoingGreenGrapevine.com

sounds like a cycloturbine - this may give you a few ideas - www.windstuffnow.com/main/darrieus_type.htm

That is GENIUS!

SIMPLE and effective design!!! Bravo to the designer!!

My Website: www.GoingGreenGrapevine.com

The cycloturbine needs to be steered into the wind to pivot the blades taking away all the advantages the vawt has.Plus complicatsd to build.

The Gyromill uses vertical airfoils and needs no mechanisms to run at tsrs >2.Swirly winds have no effect.

I gave the airfoils on mine a bit of a twist for the rotation.Airplanes dont fly in little round circles.

Ok Im am using a new type of aerofoils that I found.
These are open at the back so they catch the wind at low speeds but then can still create lift.

The wings are like usual wings at leading edge but at back are open.

Thanks for your advice so far,

James

Got a pic or link.Your name suggests Darrius and your description suggests sav.

Here is a link to another forum article with a pic of my prototype on it. The open wings at the back give the wind turbine a self starting ability.
I will be using these wings for my next design

Regards,

James

Sorry but I didnt add the link.

Any way here it is: http://gotwind.forumco.com/topic~TOPIC_ID~741.asp

James

Thu Jan 01, 1970 1:00 am by vawtman

http://www.otherpower.com/images/scimages/5119/profile.JPG

This is pic of what i call a fish foil since i thought of it while holding onto a fish.

The bigger one is used on my 8ft turbine and the smaller one is for a 4ft turbine i have yet to build.
I found by concaving the inner portion of the blades there are no startup issues.

It was quite the happy day when i tested it.After so many failures.

Mark