A few points regarding my wind turbine

[T C]

TL;DR

I recently have made a wind turbine and tested it (without any dynamo/alternator attached) and found the RPM to be around 360. What to know from others how my turbine has performed.

I recently have made a wind turbine based on Michael Waters basic design. It has 25 cm diameter and two bearings are attached to the shaft. At first, I have tested by putting it at the top of a ball point pen under a ceiling fan. You can see how it rotated in this video. But when I added the shaft and attached two bearings to it, the RPM reduced drastically in the same condition. You can check that from the second video. I now have tested it by putting it before a table that can generate around 6 m/s wind velocity and found the RPM to be around 360. You can check that from the third video. I am sure that with better bearings, the RPM can be much higher. Still I want to know how it has performed from others.

 

[Flyboy]

I’m… not seeing any videos attached or linked?

 

[T C]

For some unknown reason, I haven't been able to post any video. Can I send those to your inbox?

 

[berkeman]

For some unknown reason, I haven't been able to post any video. Can I send those to your inbox?

I don't think PF supports video attachments. You need to host them on YouTube or similar and link to them here.

 

[T C]

In that case, kindly believe my words for now.

 

[Flyboy]

Then can you provide some photos for us? It will help tremendously if we can see what you are working with.

After all, a picture is worth a thousand words.

 

[T C]

 

[256bits]

http://www.rexresearch.com/waterswind/waters.html
Is that the turbine?

 

[Flyboy]

View attachment 358675View attachment 358676View attachment 358677

Thank you for the pictures.

I suspect that your assessment that better ball bearings will improve performance is spot on.

Out of curiosity… is there a difference in rotational behavior, such as how much force is required to start turning it, or how long it takes to spin down from a certain speed, between being oriented horizontally, with the rotation axis aimed at the horizon, vs vertically with the axis aimed towards the sky? If there is, I would advise checking your bearings for play. If not… are the bearing prepacked with a grease?

 

[T C]

http://www.rexresearch.com/waterswind/waters.html
Is that the turbine?

With some modifications.

 

[T C]

Out of curiosity… is there a difference in rotational behavior, such as how much force is required to start turning it, or how long it takes to spin down from a certain speed, between being oriented horizontally, with the rotation axis aimed at the horizon, vs vertically with the axis aimed towards the sky? If there is, I would advise checking your bearings for play. If not… are the bearing prepacked with a grease?

As I have told you before that first I have tested it by putting it on a ball point pen under a ceiling fan. And in the second time, I have tested it under the same ceiling fan after the ball bearings being attached. If I can show you the videos, the differences will become crystal clear.

 

[Flyboy]

As I have told you before that first I have tested it by putting it on a ball point pen under a ceiling fan. And in the second time, I have tested it under the same ceiling fan after the ball bearings being attached. If I can show you the videos, the differences will become crystal clear.

Then post them to YouTube with the option to keep them private but viewable via the link if you’re concerned about privacy. I used that approach last year on a different forum when I needed audio of an unusual noise on my truck.

 

[Ivan Nikiforov]

Good afternoon! The link below contains a description of the wind turbine. It seems to me that it has some disadvantages related to operation. Such a turbine has a large area. To hold it in a gale-force wind, you will need a very powerful support. In a classic turbine, the blades are mounted like a weather vane. This allows you to reduce the load in case of gale force winds. The proposed turbine will be clogged with snow and ice in winter. This makes its use possible only in regions where there is no snow and ice. In addition, the power of a wind turbine is proportional to the second power of its diameter. Therefore, classic industrial turbines have a large-diameter screw.

https://img1.wsimg.com/blobby/go/56...-c5afe1b4bf73/Waters Wind Turbine (3) (1).pdf

 

[russ_watters]

OP has brought this up previously, as discussed in the threads at the top of the "similar threads" list below. The problems/limitations mentioned by @Ivan Nikiforov above are discussed in those threads as well.

The takeaway from this latest test confirms predictions in the prior threads. Specifically, if adding a shaft to the turbine causes a large drop in RPM that tells you the power/torque are very low.

For testing purposes of I would mount the turbine directly on the shaft of a dc motor-generator to reduce the loss. It will probably register some output, but I would not expect much.

 

[256bits]

It will probably register some output, but I would not expect much.

What is noticeable is the lack of any power curve or data for the device.
The author has his own list of impressable credentials for someone to be impressed with; but within the pdf, and the site that I gave, surely the author could have added some technical data. to back up the claim of being
" Using a wind tunnel to compare Mike's design to the conventional 3-blade design, they were getting numbers like 50x more efficient. FIFTY TIMES!!"
since he wants to share with the world.

Anyways, air is low head, somewhat medium/high velocity.
The propeller type, immersed within the moving fluid without a casing, is the choice usually in such an environment, outclassing the other reaction/impulse type turbines which operate more effectively under higher pressure.

Even so, Maybe I will build a prototype one someday just for fun!

 

[256bits]

PS.
I reminds me of that coke bottle in a wall thing for cooling using the wind.

 

[T C]

It's a 25 cm diameter turbine rotating with 360 RPM at 6 m/s wind velocity. That means the velocity at the periphery of this turbine is 4.71 m/s. Do you think it's a bad performance?

 

[T C]

Even so, Maybe I will build a prototype one someday just for fun!

If you wish, then I can share the STL file with you. Make a 3D printed prototype and test it in your own way.

 

[russ_watters]

What is noticeable is the lack of any power curve or data for the device....

" Using a wind tunnel to compare Mike's design to the conventional 3-blade design, they were getting numbers like 50x more efficient. FIFTY TIMES!!"

I think we figured out in a prior thread it was an edge case, like very low flow where this turbine can start but a conventional one can't. But yeah, a performance curve is what's needed and isn't being providing. It's a glaringly basic omission.

Even so, Maybe I will build a prototype one someday just for fun!

[And test] I was going to say it would make a good science fair project. Pretty easy, which is why it's so glaring an omission.

 

[256bits]

If you wish, then I can share the STL file with you. Make a 3D printed prototype and test it in your own way.

Thanks. I'm fine with just the basic concept.

 

[pbuk]

It's a 25 cm diameter turbine rotating with 360 RPM at 6 m/s wind velocity. That means the velocity at the periphery of this turbine is 4.71 m/s. Do you think it's a bad performance?

This highlights (one of) your fundamantel misunderstandings. Rotational velocity tells us nothing about the performance of a turbine: a disk drive rotates at 7,200 RPM but the propellor of an oil tanker typically rotates at less than 100 RPM, which do you think uses more power?

Or looking at it from another angle, if your turbine slows down measurably when a small amout of power is being lost in bearing friction, how much power do you think it will be able to provide to a generator?

You should take heed of the advice of @Ivan Nikiforov, @256bits and @russ_watters. Making outlandish claims supported by irrelevant data without providing any relevant data as Waters is doing is one of the signs of a crackpot or a fraud and you should treat his designs with appropriate caution.

 

[T C]

The maximum power achievable by any turbine of 25 cm diameter at 6 m/s wind velocity is 3.91952882475 W. Therefore even just 1 W loss by the bearings is a significant loss for this turbine. And usually RPM is related to moment of inertia of the rotating body. The total mass (including shaft mass) of this turbine 435 gm and it's diameter is 25 cm.

 

[russ_watters]

The maximum power achievable by any turbine of 25 cm diameter at 6 m/s wind velocity is 3.91952882475 W. Therefore even just 1 W loss by the bearings is a significant loss for this turbine.

Yep, 25% would be a big loss. But I suspect yours is much worse.

And usually RPM is related to moment of inertia of the rotating body.

No it isn't.

But anyway, as always it is a frustrating waste of time that you'd rather argue about side issues than conduct simple tests.

 

[pbuk]

Making outlandish claims supported by irrelevant data without providing any relevant data ... is one of the signs of a crackpot

The maximum power achievable by any turbine of 25 cm diameter at 6 m/s wind velocity is 3.91952882475 W. Therefore even just 1 W loss by the bearings is a significant loss for this turbine. And usually RPM is related to moment of inertia of the rotating body. The total mass (including shaft mass) of this turbine 435 gm and it's diameter is 25 cm.

QED?

 

[berkeman]

Therefore even just 1 W loss by the bearings is a significant loss for this turbine.

1 Watt of power loss to the bearings of such a small turbine is crazy. You can feel the heat from 1 Watt, and if you can feel your bearings heating up like that for a tiny experiment, that is bad.

Thread is done. Please do not try to start a new thread about this unless you post quantitative data like you have been asked for in this thread.