Feb
4
Fact Check on the New Wind Turbine Design
February 4, 2008 | 11 Comments
Last week saw the FloDesign wind turbine concept license to FloDesign Wind Turbine Corporation as a spin off from FloDesign. Hat Tip to Al Fin! The new company is being set up to develop prototype units and work out the fabrication and marketing of the new design.
The FloDesign model looks to be based on the venturi, named after the discoverer, G.B. Venturi, an eighteenth century physicist. The venturi is essentially a hole in the wall in front of a moving air mass. Venturi’s discovery was that air moving through a venturi would gain speed. Much has been developed over the past two centuries in compressed air engineering to exploit the property. For our purposes the noteworthy aspect is that a venturi mounted in a manifold where one inlet is the incoming air and one is at static pressure the exiting air can pull the static air down close to a vacuum in the low pressure area behind the inlet.
What the drawings of the new FloDesign device offer, if they are accurate, is the venturi hole is in part occupied by the blade set of the generator drive. The ring is likely a design that brings the aspect of a wing to achieve a negative pressure compared to the wind air flowing by and through the device.
By a wing, think of a small plane or glider wing with the shape set to flow smoothly over one side and the other with a bulge to speed the air and create a low pressure zone to make lift. Then roll it up, one end to the other to make the ring.
The drawings suggest that FloDesign has reached deeper into their experience and knowledge to increase the low-pressure area behind the generator blades. The double ring look suggests that the flow models offer a deeper low pressure and some compensation for the blade and generator blockage in the inner annulus or hole.
Venturis are usually quiet operating devices, compact, and simple making them lightweight. Some designs offer ways to control the work being done. Many readers will recall the “venturi” from the days of carburetor gasoline systems and some might recall the level of effort at that time to improve the flow dynamics. The carburetor used the venturi to for a low-pressure zone to pull fuel into the airflow. Thus, some readers will recall the view in a carb where high incoming flow could pull a fast moving fuel mist into the stream.
So its safe to save that the principles in the FloDesign device are very good. I saw an early attempt to create a wing generator based on the venturi as early as 1973. The single ring was effectively a short-barreled low-pressure zone provider. It seems that experienced high-powered engineering and some innovation has FloDesign device scaled up and ready for prototype builds and tests. In FloDesign’s favor is the near 100 years of experience in airflow dynamics. In hindsight, it’s a surprise this hasn’t come sooner.
Just who are these guys? FloDesign is a contract-engineering firm. A company one might go to for specialized services to solve, test, explore, replicate or any number of skills that would need an independent work team, or one that has a skill set that overreaches a companies staff or has a short term need. A quick look at the client list provided on the website leads one to realize this is one of the U.S.’s go to teams in their field. There is also a page that lists the principles and briefs on their roles and experience.
The significance of the design addressed another aspect of the open propeller design currently in mass production. As the propellers of airplanes have given way to turbojets, a principle applies to open bladed drive sets. Betz, a German physicist offered in 1919 that a wind turbine would have an upper efficiency limit of 59.3%, which holds true today and sets the performance standard to measure a blade set.
As in a turbojet the FloDesign device is shrouded and incorporates a mixer pump action to draw more air in. Then the second ring acts in a cascade fashion to amplify the effect. See this series of pages about the design.
The easy to predict problems are the total “drag” as the whole of the unit will offer wind resistance. How that compares to the drag of an open blade design isn’t available yet. Another question is the cost to manufacture. As the prototypes are to be constructed, the hard information about fabrication is yet to come. There will be other issues to work out. not the least being the huge momentum of the existing open blade type’s installed base, manufacturing plants on line, and experienced installers and maintenance people already growing rapidly.
But the bait is mighty attractive – The opening salvo is a half the diameter, producing half again more power, at 25 to 35% lower cost. If the design can be manufactured so that the design offers a minimum change to the current industry practices, the switch could come very fast indeed. And the volume of energy fed to the grid would grow even faster.
On the other hand I don’t see that the proposed turbines will compete with the large wind generator sets. The FloDesign site shows the comparison of the 12 ft FloDesign to a 24 ft blade set that by a wind speed of 10 mph has the FloDesign up to 1000 watts and the blade set barely working.
This early its hard to say with any certainty that the FloDesign turbine will revolutionize the business. But the wind power industry has gotten very big very fast and the willingness to adopt innovation is no problem. These facts offer the FloDesign people a license scenario in which the volume is already there, so the license negotiations will consider volume as a principle. It’s a offer of evolutionary improvement. I hope that’s kept in mind because this design offers a lot of new potential, even where the wind is already being harvested.
Comments
11 Comments so far
It’s about time. I think these guys have the most beautiful design I’ve seen. We have a wind farm 5 miles from our house. It keeps me up at night! This is awesome. Has anybody invested yet?
[...] behind the latest wind turbine from FloDesign. … flodesign is a contract-engineering firm. …http://newenergyandfuel.com/http:/newenergyandfuel/com/2008/02/04/fact-check-on-the-new-wind-turbine…FloDesign :: Aerospace Technologies EverywhereStanley Kowalski Jr., CFO of FloDesign, Inc., Present [...]
please update me on your progress and when we can buy / install these great type of wind turbines and what will be the price / KW
also please send me a user name and password to access your flodesign website
regards
Is there any evidence that this type of design may function better with ecological issues and siting concerns, and mitigate against bird collisions, bat fly-bys, and other habitat and ecosystem issues?
FloDesign is a beautiful design for low speed winds and great power, but then Dragonfly was design has four Wind turbines in one. It is self powered for generating electrical energy in no wind at all… Dragonfly is nothing short of being the “Next Generation Wind Turbine!”
http://www.dragonfly-windturbine.com
Check it out…
Thanks for your website.
We are interesting your windturbine design.
Please inform us more detail brochure.
I am very interested in developments and see the offshore applications overcoming most of the installation issues delaying ready acceptance.
I am very interested in developments and see the offshore applications overcoming most of the installation issues delaying ready acceptance. (Sorry for the duplication but the first one didn’t include email address.)
[...] a hole will gain speed because of differences in air pressure. The web site New Energy and Fuel has an interesting write-up on the science and engineering behind the design [...]
[...] a hole will gain speed because of differences in air pressure. The web site New Energy and Fuel has an interesting write-up on the science and engineering behind the design [...] http://blog.byohosting.com/2010/01/20/kleiner-perkins-doubles-down-on-a-%e2%80%9cshrouded%e2%80%9d-wind-turbine-design-earth2tech/
[...] a hole will gain speed because of differences in air pressure. The web site New Energy and Fuel has an interesting write-up on the science and engineering behind the design [...] http://www.karangoel.in/kleiner-perkins-doubles-down-on-a-%e2%80%9cshrouded%e2%80%9d-wind-turbine-design/