Performance of Waters' Wind Turbine in open spaces

[T C]

TL;DR Summary

Came to know about the turbine invented by Michael Waters and gone through some the website and some other sources. But haven't been able to see any material or paper regarding how this turbine is performing when used in real life.

I recently came to know about Waters wind turbine. That turbine has been invented by Michael Waters. In their website, there are many advantaged written about it. But, when I started to search outside to check how effective it is in real condition, haven't got much information instead of a few short reels and some site. I haven't found any paper written on this turbine anywhere. Want to know anyone here have any information about real life testing of this machine available to them or not. If someone have, hope he/she will share it here. I simply want to verify what is written in the website is true or not. And that can only be confirmed by any third party will verify the claims.

 

[berkeman]

Paging @cjl

 

[bob012345]

I think your best bet is to try and contact Mike Waters directly.

 

[russ_watters]

...or maybe just drop it. It's "patent pending" and the website displays both fundamental misunderstandings of basic concepts and impossible or intentionally misleading claims("up to 122x more efficient..."). Not a good sign.

If he had real testing data he'd probably have posted it.

 

[T C]

I have seen papers on other kind of turbines. And as far as I know, there is no restriction in researching this model. Then why no other researcher has tried to verify it so far? It's pretty simple and not hard to make one. And Robert Murray Smith has made a 3D printed model and made videos of that. If he can do that, then why not any other researcher can do it.
I have found this video very interesting. Some research should be conducted to verify whether the claims are true or not. I have a CAD design of a model ready in my hand. If anyone want to make a 3D printed model and test it, I can share it with him/her.

 

[Baluncore]

I haven't found any paper written on this turbine anywhere.

A wind turbine should operate over a range of wind speed and direction, while surviving the windstorms that threaten the investment. Durability is more important than efficiency.

The problem I see with the Waters design is that it operates at very low wind speeds. Energy is proportional to the square of the wind speed, so the hardware will yield little energy from each site. If there is then a windstorm, while it might be turned sideways, it maintains a high windage section from all directions. There is no orientation in which to hide.

Because it has high inertia and momentum, (all blade mass at the periphery), it probably cannot be stopped in a crosswind. Like in the old wooden post mills, there will be problems, culminating in brake or alternator fires during storms. That is why there are so few historic post mills remaining today.

Any attempt to change direction while spinning, will require a strong tower to handle the gyroscopic forces. I am seeing the heads broken off sunflowers after a storm.

The design seems to be optimised as a fixed RPM blower, rather than a turbine for energy extraction from real world winds.

 

[bob012345]

The problem I see with the Waters design is that it operates at very low wind speeds. Energy is proportional to the square of the wind speed, so the hardware will yield little energy from each site.

The claim is it starts at lower wind speeds. Why would that limit its operation to only lower wind speeds?

 

[Baluncore]

The reason why there is no data, is that no one has built and installed a Waters turbine, that has lasted long enough to generate data. For the same cost of materials and construction, more simple three bladed turbines could be built, in a windy place, that would all survive, generating hundreds of times the power.

The claim is it starts at lower wind speeds. Why would that limit its operation to only lower wind speeds?

Airflow over the fixed blades is optimised for low speed operation, when there is very little wind energy available. At higher wind speeds, the blades will interfere, and airflow through the turbine slots will become turbulent and choked.

The optimum number of blades is proportional to the reciprocal of the RPM. The ratio of lowest to highest wind speed will be less, increasing efficiency, if low speed operation, when there is little wind energy, can be avoided.

The alternator shaft must be of sufficient diameter to handle high torque at low speed, while the bearings that the shaft runs in, must be of smaller diameter, if they are to survive at higher speeds. The gyroscopic forces, when turning the head, must not bend the shaft, nor damage the bearings, that are very difficult, if not impossible, to replace.

 

[T C]

A wind turbine should operate over a range of wind speed and direction, while surviving the windstorms that threaten the investment. Durability is more important than efficiency.

The problem I see with the Waters design is that it operates at very low wind speeds. Energy is proportional to the square of the wind speed, so the hardware will yield little energy from each site. If there is then a windstorm, while it might be turned sideways, it maintains a high windage section from all directions. There is no orientation in which to hide.

Because it has high inertia and momentum, (all blade mass at the periphery), it probably cannot be stopped in a crosswind. Like in the old wooden post mills, there will be problems, culminating in brake or alternator fires during storms. That is why there are so few historic post mills remaining today.

Any attempt to change direction while spinning, will require a strong tower to handle the gyroscopic forces. I am seeing the heads broken off sunflowers after a storm.

The design seems to be optimised as a fixed RPM blower, rather than a turbine for energy extraction from real world winds.

Just to be sure what you are saying, testing is necessary. And, want to know just one point, at least you agreed that at low wind speed it can perform well or not.

 

[Baluncore]

Just to be sure what you are saying, testing is necessary. And, want to know just one point, at least you agreed that at low wind speed it can perform well or not.

Is that a statement or a question?
An efficient Waters turbine would be destroyed in the first windstorm.

 

[cjl]

Paging @cjl

OK, let's take a look...

The goal of a wind or water turbine
Convert the force of a fluid passing through a given area into electrical or mechanical force.
The Betz limit is discussed here.

OK, true enough, but I'm already having my woo senses start to tingle. Let's see what this Betz discussion is...

The Betz law applies to all Newtonian fluids. It defines the maximum theoretical efficiency that a wind turbine can achieve as 59.3%. This is based on the total available energy of the wind at a given speed. All current commercial wind turbines are designed based on this same assumption and most wind turbines are considered to be 34% to 45% efficient.

This is a huge mistake

The Betz limit is based on the obvious assumption that extracting energy from wind will reduce the speed of the wind. Betz only applies to the point of extraction. What the Betz limit ignores, or more correctly, what resultant design assumptions throughout the global wind industry have ignored, is that you can also increase the speed of the wind prior to extracting energy with no penalty. Double the wind speed and the available energy increases by 8 times.

Betz applies to *all* incompressible external flows that you're trying to extract power from. This "gotcha" that he's trying to claim here is false - any design involving some kind of a concentrator (like the mountain ridge he mentions in the following paragraph) still must ultimately follow the Betz limit, you're just increasing the effective collection area. Yes, this increases wind energy available, because increasing collection area always does, but it's not a magical "get out of the Betz limit free" card.

Currently, only the outer 30% of a typical wind turbine blade produces any meaningful torque and that blade area is less than 5% of the total disk area. In addition, tip loss occurs at the maximum point of leverage. Aerodynamic efficiency is utilized but no attempt is made to divert or accelerate the air prior to or after extraction. In other words, the drag side of the equation is completely ignored.

Oh dear.

This is all basically 100% wrong. Torque is produced along the entirety of the blade length, though of course the outer 30% is the most important because that's about half the total collection area, and you have more efficient airfoils out there because you can make them thinner with better L/D because the root airfoils have more stringent structural concerns.

However, the root 70% still makes a bit less than half the power on a modern turbine, and it's not ignored. Also, low rotor solidity (the "only 5% of the total disk area is occupied by blade" part) doesn't mean that you only affect a small portion of the wind passing through. It's just a design factor. With a low solidity blade, you run a higher tip speed ratio, so you need to balance those factors when optimizing the design, but you still absolutely interact with all the air passing through the disk.

This is not necessarily intuitive of course - it looks like a ton of air is passing between the blades, but the reason this works is because the blades are traveling at a high multiple of the wind speed - usually around 10x or so. Because the blade is traveling 10x faster than the wind, air that passes through the large opening will still shortly have the blade pass right behind it or will have had the blade pass right in front of it shortly before it went through the opening, and thus the turbine still effectively interacts with the entire disk of air.

There's a really cool video that helps visualize this here:


Note how little the air from one blade passage has moved before the next blade comes by?

Returning back to the original page (there's a lot more wrong on that Betz limit page, but I'm trying to not write too much of a novel here).

Current designs maximize aerodynamic efficiency like an aircraft. This results in long thin wings that comprise less than 5% of the total disk area in the region of maximum torque (the tip). Much of the air passes through unaffected or in a region that contributes low torque (the root). Only the tip of the blade maximizes leverage.

I've already explained why this is wrong.

Now, with the Waters design:

There are two choices for accelerating flow. Divert around an object or constrict through a narrower path. Diverting flow to the outside provides more leverage for a given size object and enables a simpler design. Generally, large costs more than small. Complex costs more than simple. Here is a basic design that meets the criteria.

In the above illustration, all of the flow has to go around the back plate, accelerating in the process. A band of blades is mounted around the perimeter at both the maximum point of leverage and maximum flow velocity. As a result, all of the fluid is utilized and accelerated to maximum velocity prior to use.

What he's missing here is that due to the high blocking caused by this design, a large proportion of the air will just flow around the entire turbine. This doesn't "utilize all the fluid", it actually will force a large proportion of the air to just bypass the turbine entirely. In addition, he continuously makes the mistake of assuming drag doesn't matter, but the direction drag operates at the blade tips or in his blade ring is nearly directly opposing the desired torque. Drag is opposite the relative wind, and because the turbine spins, that means drag *opposes this spin*. Wind turbines are designed for maximum L/D for very good reasons, and not just because the designers are naively following aircraft design principles.

I originally designed the Waters turbine to prove a point for a lecture I gave regarding Open System Physics and Thermodynamics. At the time I had little interest in wind turbines but had been involved in aviation and aerodynamics most of my life. The wind industry made an easy, somewhat devastating example.

As a general rule, if you're not in a given field, and you look at that field and think "obviously they're doing everything wrong", it's vastly more likely that you're missing something than that everyone in that field's history has been an idiot.

(Relevant XKCD)

Compressing air increases temperature. Lowering pressure reduces temperature. This is basically how an air conditioner works. The Waters turbine uses drag to create 3 different pressure zones in addition to ambient. As kinetic energy is extracted, temperature drops.

Even a small thermal differential represents a considerable amount of energy potential if designed correctly. With the 4 month physicist study, optimizing this showed a COP of up to 20 which means we were tapping a second thermal energy source. At first glance this appears to be a case of asymmetric thermodynamics but in reality the kinetic differential is just being exploited more efficiently.

This is a strange aside - at normal wind speeds and pressure coefficients you'd encounter at those speeds, temperature changes within the flow are totally negligible. I'm not sure why he's trying to even bring thermal changes into this at all, but we can absolutely disregard all of this. Bringing a 20 m/s flow to stagnation causes a temperature rise of less than a quarter of a degree celsius, and 20m/s is faster than most of his claimed windspeeds anyways.

In my tests, the conventional design was a molded precision product with an accurate airfoil. Mine was far from optimized, using no airfoils (concrete vent) in order to establish the source of the efficiency gain that was in addition to aerodynamic gains.

Comparing my 4' design against a stock 5' three blade under the same load, the conventional product starts at over 7 mph and produces very little torque or rpm at that speed. My turbine, under the same load starts at under 1 mph. If the square force relationship is used that is 49 times more force required to turn the conventional design. If the cube rule is used the difference is 343 times. Then there is a size difference. The actual formula is more complex and varies with wind speed but the results are interesting. Startup velocity is just one factor but this shows that a much broader wind velocity range can be utilized.

Under extreme shaft load, the conventional turbine would not turn even at 28 mph. My design in the same conditions self starts at 11 mph.

I strongly suspect his reference turbine here has a fixed blade pitch. This means that at low RPM, the blade will be nearly entirely stalled, and producing next to no power. It's unsurprising that under load, it would struggle to self start. For proper comparison, the turbine needs some kind of RPM control on it, adjusting back torque to keep it at approximately a fixed tip speed ratio (ratio between tip speed and incoming wind speed to maintain good angle of attack across the whole blade).

If he actually allowed the HAWT to unstall, he'd find that it would make substantially more power than his design. You need to let it spin up before you apply substantial load, particularly for a fixed pitch turbine. As a result, his test results are totally useless. It's also well known that if your goal is low-RPM torque, particularly stall torque, you do want a pretty high solidity rotor (having more of the disk area occupied by blades) - a good example of this is your classic US western "windmills" that drive water pumps for livestock and such. This gives more starting torque, but actually less peak power because you have more drag as you try to increase RPM.

Also, larger scale wind turbines use pitch controlled blades to help alleviate this starting problem - they do still perform optimally at fairly high RPM (relative to their diameter and incoming wind speed), but to aid starting, they can pitch the blades more towards feather so they are not stalled as they start up. As the rotor accelerates, the blade pitches more and more towards operation, maintaining a good non-stalled angle of attack the entire time. You can see that clearly in this video here, for example:


Basically, his design might work well in some small niches, but it'll always make less power than a well designed horizontal axis 3 blade turbine, as long as that 3 blade is actually operated properly and not just forced to sit there with its blades stalled the whole time.

 

[T C]

An efficient Waters turbine would be destroyed in the first windstorm.

Maybe! But even in that case, would it be able to generate more revenue than its own cost? That part need to be analyzed. It can be built easily and at very low cost. On proper research, I am sure some way would be found so that it can be shut down and saved in case of thunderstorm. And if flow at the periphery will reach sonic velocity and it become choked, what level of wind flow is necessary for that?

 

[Baluncore]

On proper research, I am sure some way would be found so that it can be shut down and saved in case of thunderstorm.

Thunderstorms are not the problem, it is windstorms that destroy turbines. Lightning strikes will destroy the wind-shaft rolling bearings.

The circular disc backplate, even when turned back-corner to the wind, will present the tower and bearings with enormously destructive wind forces.

Give up on the Waters turbine now. You don't need to be an apologist for Waters, or do an impression of a donkey. There are good reasons why that drum configuration is used for fixed speed blowers, and not for wind turbines in the real world.

Most amateur wind turbine experimenters get hooked on the Savonius drag rotor, to their detriment. You have broken with tradition by getting hooked on the Waters turbine.

As a watcher of an amateur wind turbine group for thirty years, I have seen many "innovative" turbines destroyed by the wind. I would be most surprised, if the Waters turbine could be both efficient, and not be destroyed in the first year.

It is not a novel idea, can you point to one that is still operating?

 

[T C]

As a watcher of an amateur wind turbine group for thirty years, I have seen many "innovative" turbines destroyed by the wind.

At present, ventum turbines and Archimedes turbines are doing well in open air.

 

[Vanadium 50]

. Then why no other researcher has tried to verify it so far?

Because it takes time, money and effort, and if we spent all our time trying to reproduce perpetual motion machines and other crackpottery we would get nothing else done.

You think this is a good idea? Why don't you do it then?

 

[T C]

Because it takes time, money and effort, and if we spent all our time trying to reproduce perpetual motion machines and other crackpottery we would get nothing else done.

I am not talking about amateur individual researchers, but rather research done by educational institutes. I have seen a few papers on Invelox and some suggesting some changes. The changes suggested are very much similar to ventum turbine. And, by the way, Robert Murray Smith has already done it and made videos on that. You yourself can check it on youtube. And, can't understand why you dragged "perpetual motion machines" in this discussion.

 

[Vanadium 50]

You asked a question. That's the answer. You may not like the answer, but that is the explanation.

You are free to argue that "this isn't worth my own time, effort and money, but it is worth yours." Just don't expect it to get much traction.

 

[T C]

You asked a question. That's the answer. You may not like the answer, but that is the explanation.

There are many parts not explained in you explanation. And you asked me to do that and I have shown you it has already been done. You yourself can check it.

 

[russ_watters]

I am not talking about amateur individual researchers, but rather research done by educational institutes.

Wasting the time and money of professional researchers is even worse than that of amateurs/hobbyists. At least amateurs/hobbyists aren't expected to be productive.

And, can't understand why you dragged "perpetual motion machines" in this discussion.

Impossible efficiency/power production claims = PMM.

There are many parts not explained in you explanation.

Having 5 major flaws is enough to drop it. Getting 5 more would make it worse, not better. You should learn to spend your own time time better/detect when you are wasting it on something that won't work. This isn't worth any more of anyone else's time here, so it is locked. You are of course free to spend as much of your time and money on it as you want, just not here.