Most efficient wind turbine on planet?

[Generator]

https:// winergy. xyz/

Video demo : removed

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Moderator edit: site link disabled, but you can look further if you want.  Proceed at your own risk.  Youtube link removed.  Principal reason is that the website claims an association with NREL when it actually does not.  NREL does not fund projects in India.
I would like to add that giving traffic to YT channels by posting and clicking links to their videos increases the revenue of the channel owners.  By posting videos of known snake-oil you are putting money in their pockets, whether they are scammers or just self-delusional.  By clicking links on these posts you are also building links that trace back to Fieldlines that Google and all the other DNS organizations will track and use to rate our site.  Welcome to the new internet where everyone watches everyone. 
-SPARWEB
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[clockmanFRA]

HHMM seen these type of designs before.

He says that 8 feet diameter would give 3kW to 4kW,  yea in hurricane conditions just before it destroyed itself.

I understand that the blades with this design have real bad drag issues.

[kitestrings]

I wish people would reconsider these over-rated claims. They do nothing to help promote the technology, and anyone who buys in - in the end is sadly disappointed.

Bunk.

[Mary B]

First thought... what a piece of junk LOL second thought... winds here would tear that thing to pieces.

Snake oil...

[taylorp035]

That seems rather dangerous to be down wind of a machine that looks like that.

[Scruff]

I got "The Oceans". What was your answer? 

[Astro]

ummmm.
lol.
Not saying that a design that is supposed to look like a jet turbine is horrible, as I have seen worse.
But my first question is how did he get the wind to come up and then go back calm?
Second thing is, it reminds me of my first sterling engine I built all by hand. I bent a piece of round stock with a vise and hammer and welded in spokes for a flywheel. Dang thing almost came of the table with a can of sterno under it.
In all fairness, I was working with minimal equipment and doing it on my break time at work. It was one of those I wonder if I can,.....type things.
But you know in the end what he has is an old style wind mill with a cone to catch the air around it. Those mills were not designed to spin fast OR to make electricity.
Congrats on trying though. Did not fail, just figured out what doesn't work.

[Mary B]

I think he was on a scooter of some sort...

[topspeed]

I think he was on a scooter of some sort...

Then the result is not even valid.

[SparWeb]

Most efficient wind turbine on planet?

MINE   

[Astro]

I think he was on a scooter of some sort...

So as far as we know he was going 20 mph into a 10 mph headwind.
I mean if you are going to show how efficient something is, I just do not think that video accomplished that.

[Generator]

Here is another video with more details https://youtu.be/fLXyD3haLRM
Would love to read comments from experts, who have experience in building similar windmills.

[Adriaan Kragten]

This is a clear example of what you can get if people start to design wind turbines without the basic knowledge of the aerodynamics of wind turbines and ducted rotors. Already in 1926 Betz has found that to get a maximum Cp, the flow through the rotor has to expand such that the wind speed in the rotor plane is 2/3 of the wind speed V far before the rotor and that the wind speed far behind the rotor is 1/3 V. So the wake is expanding (see figure 4.1 out of chapter 4.2 of my public report KD 35). They show a computer drawing of the wake which is completely fake as the wake isn't expanding.

Betz has found that the maximum Cp is 16/27 if there are no losses. In chapter 4.3 of KD 35, I give four reasons why the real Cp is lower than 16/27. The first reason is wake rotation. The losses due to wake rotation are stronger if the design tip speed ratio is lower. The required number of blades are higher if the design tip speed ratio is lower. In the movie you can see that they use a rotor with many blades with a large chord. So this is a rotor with a low design tip speed ratio and so with high losses due to wake rotation. This is at least one reason why this rotor can't have a high maximum Cp.

It is possible to get a maximum Cp which is higher than the Betz coefficient if a ducted rotor is used. However, this is only possible if the duct has a shape such that the wake is expanding much more than for a rotor without a duct. This means that the main part of the duct must be situated behind the rotor and that the maximum diameter of the duct must be much larger than the rotor diameter. But in the movie you can see that the duct is situated in front of the rotor and that it is expected that it pushes the wind in the rotor. This isn't working that way. The way to get an increase of the mass flow through the rotor is to create an under pressure behind the rotor and therefore you need a large duct behind the rotor. So the claim that this is a very efficient wind turbine is completely nonsense.

[MattM]

Wakes don't expand, but the turbulence does.  Semantics.

[Astro]

"The way to get an increase of the mass flow through the rotor is to create an under pressure behind the rotor "

Just like lift on a wing.
The thing with nature and thus physics, because physics is based on the laws of nature, is that you can not beat nature. All you can do is create a environment that is either more or less conducive to what the desired outcome is.
People tend to forget that simple rule. They think they are in charge and the laws of nature are going to bend for them. The best, and most efficient thing ever built will be that which compliments nature and uses what it is giving to it's fullest capacity. Just like pushing a child or football player to be their absolute best. You are not instilling or giving them their gift, you are just bringing out a potential that was already there.

[Adriaan Kragten]

Wakes don't expand, but the turbulence does.  Semantics.

It depends on the definition of what the wake is. What I have learned is that the wake is that part of the flow which has been influenced by extraction of power from the wind by the rotor. The boundary of the wake touches the blade tips and it is the boundary which is expanding. So outside the wake you have the undisturbed wind speed V. It is true that there is a lot of turbulence in the wake behind the rotor and this turbulence makes that this part of the wake is mixed with the surrounding air. This mixing makes that far behind the rotor, again you have the undisturbed wind speed. Betz has not taken this aspect into consideration when he derived the formula for the Betz coefficient but I expect that you don't get a higher coefficient if you do so.

[MattM]

I think the premise of Betz was the actual potential.  Disturbed air will never become faster than the original straight-line windspeed without an external influence, so he's 100% correct in his reasoning.  His limit is basically not limited by the influence of drag or lift, but rather mechanical advantages.

[Generator]

HHMM seen these type of designs before.

He says that 8 feet diameter would give 3kW to 4kW,  yea in hurricane conditions just before it destroyed itself.

I understand that the blades with this design have real bad drag issues.

He mentioned the output at 11 or 13 m/s wind speed. That's the wind speed all commercial Wind turbines give the output rating. So in hurricane, it will increase in proportion of cube of velocity as per formula.

[Astro]

I think the premise of Betz was the actual potential.  Disturbed air will never become faster than the original straight-line windspeed without an external influence, so he's 100% correct in his reasoning.  His limit is basically not limited by the influence of drag or lift, but rather mechanical advantages.

 I think that eventually, maybe 200 hundred years from now, idk, someone with money is going to figure out a way to make a wind turbine somewhat like a huge turbo. Where they capture or harness a large volume of wind with a shroud or whatever, then run it through veins and have it come out in a vortex. At that point you are basically creating a small sideways cyclone, hurricane, dirt devil or whatever. Then you would be able to spin something extremely fast. You can slow it or brake it by making the veins variable, just like a new turbo. Now,can we build something that can mechanically handle spinning that fast on a scale that is useful in power generation? Well IDK, it would be a heck of an undertaking.
Remember power is related to how fast the turbine spins. Granted you may need a xformer that is 4160 down to 220 (for a home sized one) as you are going to be making some really high voltage spinning that fast. Which also brings up the "is this ok for the avg person to have" and the always more important "how do we make money from it"? The really high voltage idea is exactly what Tesla was working on. They shut that down really fast after he died and they went through his stuff.

Want to find out? Take the inducer wheel of a turbo charged engine and put a plate with magnets and a stator on that side of the turbo. Start it up and give it a little gas. You might want some high voltage test equipment handy. From there all you have to do is figure out the amount of exhaust gas you are driving the turbo with. You should have an idea or two pop into your head after that. @2000 rpm your gen could be spinning at a couple hundred thousand rpms.
Just do not go back to 1985 in a DeLorean and if you do try to remember where lighting struck. LOL

But Astro, exhaust gases are pressurized. Uh and so is steam. (hence steam turbines) Or you could run a air compressor from a large torque style mill. If the old wind mills could pump water up 100 ft. with large piston pumps, I would think one should be able to turn an air compressor.
 

[topspeed]

Huge spinner helps into some extent.

[Adriaan Kragten]

This is about the same as what Enercon is doing. They have an egged shaped nacelle to cover the very big direct drive generator and blade roots which almost touch the nacelle. These rotors have a maximum Cp of about 0.5. Without a cone and without the special blades, the maximum Cp would be about 0.48. So a cone has a certain positive effect which is felt during the whole lifetime of the windmill but this goes at certain extra costs. For small wind turbines, it is more economic to accept that there is a small part in the center of the rotor which generates no energy. If the effective part of the blade starts at 0.2 R, the area of this central part is only 4 % of the total swept area so it results in a reduction of the theoretical maximum Cp of only 4 %.

The main cause why for fast running rotors, the real Cp is smaller than the Betz coefficient, is the Cd/Cl ratio. Assume that the rotor has three blades and that the optimum lambda is 6. So we use figure 4.7 out of report KD 35. In this figure it can be seen that the theoretical Cp is about 0.38 for Cd/Cl = 0.05, that it is about 0.445 for Cd/Cl = 0.03, that it is about 0.048 for Cd/Cl = 0.02 and that it is about 0.515 for Cd/Cl = 0.01. The Cd/Cl ratio depends on the chosen airfoil but very much on the Reynolds number. Big wind turbines have large chords and therefore large Reynolds numbers at low wind speeds. Therefore big wind turbines can have a maximum Cp which is much higher than for a small one. So for a small one it is important that the Cd/Cl ratio is as small as possible. A way to realize this is to make the airfoil accurately and give it a smooth surface. So one can better puts his energy in making nice blades than in making cones which have only a limited effect.

[Adriaan Kragten]

Spar Web, I see that you have locked the thread "Contra Rotating Diffuser and Shrouded Wind Turbine Design" because the claims are false. But this thread "Most efficient wind turbine on planet" deals with the same wind turbine and has the same false claims. It should therefore also be locked and the link should be removed.

[Bruce S]

Adriaan;
Sorry for the late in locking this thread of the same type of the other one. I was having fun reading some of the answers   

Locking it as soon as I post this reply 

Bruce S