Wind turbine breakthrough or hogwash

[Jeggernaut]

thread626-64614

Investigating most efficient home turbine systems and came across this product. It claims setting up a vaccuum behind the turbine and blades will double the air flow. Is this correct science? It's an ugly beast.

 

[BigInch]

I can't see Utube at work.
What is the material and energy cost involved in setting up the vacuum? That is NOT free and the typical result is that you cannot get more differential power out of a subsystem that you have to add energy to first in order to get it set up. Things of that nature are normally either bad ideas, or very bad ideas.

It's like if I could pump the water ahead of my boat out of the way, then I could use the outboard and surf down the slope too, but you will always spend more energy pumping the water out of the way than the boat will gain surfing the resulting wave.



"People will work for you with blood and sweat and tears if they work for what they believe in......" - Simon Sinek

 

[John2025]

Just taking an intuitive guess, the flared cowling might increase the effective area of the turbine to something between the diameter of the blades and the diameter of the cowling.

 

[IRstuff]

Their website:

http://www.windtamerturbines.com/wind/compare-technologies/windtamer-q-a/

Does read like hyperbole.

TTFN
faq731-376

 

[IRstuff]

This page seems more quantitative:

http://www.windtamerturbines.com/wind/compare-technologies/calculator/

TTFN
faq731-376

 

[BigInch]

10 mph average wind velocity is the first bust.

"People will work for you with blood and sweat and tears if they work for what they believe in......" - Simon Sinek

 

[IRstuff]

Altamont Pass can lay claim to that spec.

TTFN
faq731-376

 

[msquared48]

This looks more like a large college megaphone to me. Is that why they are demonstrating it at colleges?

Mike McCann
MMC Engineering

http://mmcengineering.tripod.com

 

[GregLocock]

from the technical analysis paper...my emphasis added

"The assumptions made in this report include an
augmentation factor of 2 to account for the duct effect, no furling of the turbine, and a maximum
continuous generator output at 33% above the stated generator value. In general, it was observed
from the numerical estimations that the WindTamer turbine can produce approximately twice the
annual energy output for a given swept rotor area than a conventional open rotor design.

It should be noted that the numerically predicted design performance presented in this report is in
no way a guarantee of the final, full scale, real world performance."

Yes, I think I see what you did there.

Ducted fans always seem like an attractive idea, but in pure efficincy terms you are usually better off running a higher aspect ratio open rotor. However, efficiency is a bit of a daft concept when the input energy is sort of free, you are better off lookin at power output per dollar at a given windspeed, rather than worrying about Betz.

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376

http://eng-tips.com/market.cfm?

 

[Jeggernaut]

Thanks guys. I have a remote coastal site with 80ft trees on three sides where I need to generate enough power to run a bank of pcs and data recording equipt with satelite broadband. Have question over horizontal v. vertical drives? which way do we go to get max power input for our bucks. Least wind comes from the gap in the trees so am considering 80ft tower to get max exposure.
Plus solar on the ground, but we get wind 24/7 and need power 24/7.

 

[BigInch]

You need to consider cutting down the trees in order to use wind. If you have 80ft trees and build an 80 ft tower, you are right at the level of greatest turbulence. Most energy will be lost to swiveling around to face the wind, rather than actually capturing any with the the blades.

You need solar for days that the wind isn't working. You need batteries for when the sun isn't working and you want wind for when the sun isn't working. Best thing about solar is that generally it is on a reliable 12/12 schedule. Wind is not. If you optimize the percentage of each that you should build, including the reliability factor you need to back up what could be a considerable number of days that the wind isn't working, and the consequentially low optimized percentage that typically results when betting on having wind, and the batteries you need an all cases when none are working, it certainly won't be worth building the tower. In other words, the cost of wind vs the odds against having to count on it to deliver power reliably isn't all that good.

Unless you have an exceptional location, you would be doing very well indeed to get 20% of nameplate generating capacity out of it as an end of year average. Figures of 12 to 15% are more likely.



"People will work for you with blood and sweat and tears if they work for what they believe in......" - Simon Sinek

 

[davefitz]

a similar claim for a similar device was announced a year ago at a japanese university, and more than double output was demonstrated. Ugly- yes. efficient- yes. There are likely other issues to be worked thru, such as support tower design. I think it would be useful to also apply the same principle to wind turibnes usesd to drive farmer's water pumps- short towers are the rule, and aesthetics are not an issue.

 

[BigInch]

Farmers are not the high end of the high efficiency market.
They don't need efficiency, especially if it costs more.
They just need a slow pump rate of water.
What they get is nearly free as it is.
Not even worried about the maximum amount of water they can pump.
Nothing to optimize there.
Really don't want a high efficiency, costly device that will be one more thing to break.

"People will work for you with blood and sweat and tears if they work for what they believe in......" - Simon Sinek