VAWT and grid intertie inverter ideas

[monte350c]

Came across these while surfing:

VAWT:

Bevel gears, rotating blades - check this one out. Ideas for improvement??

LINK 1

and on the same site a new idea for grid or small diesel turbine inverter intertie:

LINK 2

Ted.

[kitno455]

ok, on the ausie turbine, i think the blade moving upwind looks normal, like ed's cycloturbine, tsr > 1. the blade moving downwind will help with starting (low tsr, drag type).

but, once the thing gets above windspeed, the downwind moving blade will be an air brake, no matter how much lift the upwind moving blade makes. that will limit it to basically a tsr of little greater than 1, right?

or am i completely mis-understanding?

allan

[windstuffnow]

  Thanks for sharing that Ted.  I've seen some built very similar to that.  I recieved an email from a guy that had built one up using a chain drive that rotated the blades in and out of the wind.  Primarily a unique drag machine.  

  My cyclo turbine works in a similar fashion but doesn't completely rotate the blades.  When the cam is set to an extreem it works very well as a drag machine producing lots of torque but it runs slow, probably in the range of .5 to .7 TSR.  When the angle is brought back it runs in the 2 to 3 range.  I've been threatening to build up another one, I ended up selling both the units I made.   The larger of the two ( 3ft tall I believe it was ) would make around 90 watts in a 20 mph wind... fun little project.  I always thought of using some drums to make cyclo-Savinous... Add another one to my "wacky" windmill collection.

  Anyway, the one I'm building now has a similar set up and is chain driven.  It holds the nose of the wing into the wind all the time as it rotates and changes angles 2 times during rotation.  It incorporates a tail to monitor where the blades should be at any given time in rotation.  This is a spin off of my "free wing" design.  Allan guessed the project pretty close in my last post.  I thought it was a first but actually the design dates back to the 80's.  I was searching the patent office and found a 4 wing structure that operates on the same theory although his movement assembly won't work effectivly.  His is maintaining wing angle by use of an aileron system and the wings are not directly tied to any other controls.  I built a similar model based on his patent and it was extreemly erratic.  That was the project that sent me in the direction of the free wing.  The HAWT version worked extreemly well but the VAWT version failed.  The one I'm building now is being built from parts of all the other strange creations and it hasn't ( so far ) cost me a penny.

So much fun... so little time...

Windstuff Ed

[kitno455]

hey, i feel better now

ed, would it be possible to have a fully symetrical wing (front to rear and top to bottom) and keep it always facing into the wind, but vary the AoA as it goes round?

i guess what i mean is that at each instantaneous blade 'location' around the spinning cylinder, the wind the blade 'sees' is coming from a slightly different angle than the moment before. rather than changing between high drag and low drag like the example here, could you just rotate the blades slightly? i guess that is how your cycloturbine works, really.

or, since the 'power' to drag the down-wind moving blade faster than the air comes from the upwind moving blade, is it better to have all blades moving downwind to be free so that they pose the least drag penalty?

allan

[monte350c]

Hi Ed,

I thought this one was primarily interesting for the bevel gear drive on the wings - it seems like a fairly neat way to gain control over the angle of attack. The drive shafts could be hidden on or in one of the struts, so there wouldn't be any real aerodynamic penalty from the control mechanism.

Seems it's getting harder to come up with something that nobody has done before. But there's lots of room for coming up with practical, workable devices. Even if the starting point is a not-so-practical patent from a few years ago.

Looking forward to hearing about this one!

Ted.

[rotornuts]

Hi Ed. Do you have an illustration of the unit that used ailerons. It sounds interesting if not practical.

[windstuffnow]

  Allan,

    I'm using symetrical wings on this unit and thats exactly what I'm doing.  The wing always keeps its leading edge toward the incomming wind at any point in rotation while changing the AoA based on its position in rotation monitored by the tail position.

    So far its been a bundle of challenges and I'm not sure if the angle system is going to do what I want it to but I have a few alternatives.  I built the position monitor yesterday and installed it but ran into a couple problems I hadn't anticipated.  So I'm stalled at this point while pondering alternatives or adding "bandaids" to make this system work properly.  These problems are what keep me going.. I love a good challenge !

Have Fun  

Windstuff Ed

[kitno455]

i am getting stuck on a point here. the power to turn the mill (if it is a lift type) comes entirely from the blades which are moving against the wind. the blades that are moving 'with' the wind (but faster) are acting as air brakes, regardless of position.

at some point as the blade swings 'across' the wind it will transition between those two modes, though gradually, because the angle of incident wind will vary.

could you setup a system with control for the AOA by some sort of roller and guide system, but only on the upwind side, and on the downwind side, the blade is free to align with the wind/direction of motion? (lowest drag)

or any other way to make the crossing and down-wind blades 'disappear'. how about a hollow cloth blade that is pressurized by a big scoop on top of the vawt, and a slide valve controlled by the tail to allow the downwind blades to deflate

allan

[monte350c]

Hi Ed,

This is bound to be a challenge mechanically. But most likely worth the efforts. The largest Darrieus rotors were getting CP's virtually identical to the horizontal units. And thats with a very big torque ripple - caused by most of the power being collected at two points in the rotation of the bladeset.

So hopefully if the AOA can be varied, the rotational angle of maximum collection can be increased. Hopefully it's not too complicated - (clunka - clunka - clunka) while running

Ted.

[bparks]

I've been toying with a somewhat similar idea, a flexible blade that could change it's shape as it rotates, but not sure if there's a material that could withstand the constant flexing required.  I'm also picturing the wing built with rigid, hinged segments that change change their shape, but don't see anyway to have a true, smooth wing profile with this & it starts to have lots of moving parts.

[windstuffnow]

   Well, I looked for the sheet I printed yesterday and today and could find hyde nor hair of it.  I did a search hoping to find the patent again and haven't found it as yet.  It was one of those things I was searching for something else and going through one patent to another where there are other similar patents listed and it led me to that one.  I don't remember if I was searching for VAWT's or Venturi turbines at the time.  Somewhere in the pile of papers I have is the drawings.   I'll keep looking and If I find it I'll shoot it over or post it.  It is an interesting beast.

Windstuff Ed

[rotornuts]

Thanks Ed, I take it your pretty busy. I know when I get an idea in my head I just can't seem to stop till I work it out or satisfy myself that it's going to take alot more than that and I'll put it away for awhile. I was thinking about your idea and I made a small model of what I thought would be a good mechanism and I discovered quickly that it's easy to keep the wing pointed into the wind but not so easy to have the AOA fluctuate in the proper direction at the right time in the rotation. A simple cam system doesn't work. I was thinking about a double cam but then you have to maintain timing between the two. The best solution I've come up with so far is actually a wing warpng system. By placing an appropriatly shaped cam in the wing you can warp it how you like and when you like at the right times in the rotation. At least thats the theory. the only problem I'm thinking of at the moment is that the cam may have rotate at twice the speed of the rotor.

Anyhow if you find that patent thanks and if not that's no problem.

Have fun,

Mike

[rotornuts]

Hey I just had a thought. Maybe a double lobed cam with a 90 degree offset would work. Hmm, gonna have to try and visualize that one.

[windstuffnow]

  Hi Mike,

    Yea, the simple part is keeping the wing pointed in the correct position.  I think I have it worked out and I'm going to build the cam/control tomorrow.

    I did some searching on that machine this afternoon, had to turn my brain off the problem for a while.  Didn't find the one I was looking for but found a few that were interesting.  Some are just plain stupid but have some interesting ideas on controls...

4004861. 
         
4015911. 
         
4037989. 
         
4048947. 
         
4490623. Ropatek patent
         
4566854. 
         
4285636. 
         
4203707. Drag machine - has potential - a different configuration would be in order.
         
4137009. 
         
5518367. 
         
         

I will find that wing machine eventually.  But I think I will have mine done before I do... then it might not matter.  I'm still pushing for the first tests this weekend.  I think the cam is going to be a bit to passive but it should give me an idea of where its going.  My first design was a bit to agressive and has a high part count but still may play a part in the final design.

There is still a 15 degree lull in power on each side as the wing changes angles but it will utilize the full frontal area... We'll see

Have Fun

Windstuff Ed

[windstuffnow]

  Must be the program only sees part of the numbers?....  Here they are again...

1.  4004861
   
2.  4015911
   
3.  4037989
   
4.  4048947
   
5.  4490623 Ropatek patent
   
6.  4566854
   
7.  4285636
   
8.  4203707 Drag machine - has potential - a different configuration would be in order.
   
9.  4137009
   
10. 5518367
    
    

[rotornuts]

Thanks for that Ed, I kind have a soft spot for simple genius of the first unit. number  8 kinda uses a similar idea. My computer is to slow to run quicktime very well. I'm short 64mb of ram so viewing those was a tedious process. I'd like to have a better look but I think I'll have to wait till I get a faster computer.

Mike