Ducted Turbine Research References

When it comes to physics of the ducted turbines, researchers and scientists around the globe have concluded since the early 1900’s that ducting turbines increases energy output.

Below is a short list of work by researchers, professors, and business community.

  1. Kenneth Visser (Professor, Department of Mechanical and Aeronautical Engineering, Clarkson University, Potsdam, NY, November 2009), “Wind Tamer Turbine Performance Report”.

Quote 1: “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.”

Quote 2: “These data above indicate that the WindTamer is capable of Cp values in the 0.6 to 0.8 range, well above that of small wind turbines on the market today by almost a factor of 2, and as has been shown, above the Betz level for an open rotor. As will be shown in the next section, these values are quite close to those predicted by the design code, mRotor used at Clarkson.”

Quote 3: “The 52 inch rotor WindTamer is estimated to generate about 3,030 kWh per year, roughly 2.5 times more energy than a comparable open rotor of the same diameter, which yields 1220 kWh per year.”

  1. C J Lawn (Professor, Department of Engineering, Queen Mary, University of London, London, UK, IMechE 2003), “Optimization of the power output from ducted turbines”.

Quote 1: “An enhancement in the power coefficient of more than 30 per cent over the optimum for an unshrouded turbine can be gained, provided the turbine resistance is reduced appropriately by choosing a more lightly loaded design.”

Quote 2: “Such an enhancement is associated with a 15 per cent increase in velocity through the turbine over the freestream value.”

  1. Jifeng Wang, Janusz Piechna, Norbert Muller (Researcher at Turbomachinery Laboratory, Michigan State University, East Lansing, MI, USA, and Institute of Aeronautics and Applied Mechanics, Warsaw University of Technology, Warsaw, Poland, 2003), “ Computational Fluid Dynamics Investigation of a Novel Multiblade Wind Turbine in a Duct”.

Quote 1: “Through the comparison of power coefficient variation with thrust coefficient, it was found that a ducted turbine can be 2-3 times that of the power extracted by a bare turbine.”

  1. Chandan D. Chaudhari , Sainath A. Waghmare, and AshishP. Kotwal (Dept. of Mech. Engg., Datta Meghe College of Eng, Airoli, Navi Mumbai, and Institute of Aeronautics, and Dept. of Mech. Eng, Lokmanya Tilak College of Eng, Koparkhairane, Navi Mumbai, 2013), “Numerical Analysis of Venturi Ducted Horizontal Axis Wind Turbine for Efficient Power Generation”.

Quote 1: “The increased velocity of wind resulted in significant improvement in the kinetic energy hence power output of turbine.”

  1. H. Al-Bahadly and A.F.T. Petersen (Massey University, New Zealand, 2013), “A Ducted Horizontal Wind Turbine for Efficient Generation.”

Quote 1: “Power calculations were provided for the ducted turbine and the conventional turbine. These provided a direct comparison that was referred to as condition 1 and condition 2. This showed a theoretical power rating difference of a factor of 17, it must be shown here that the theoretical power shows the amount of power that is available in the wind flow.”

  1. Ducted Turbines International (DTI), “Ducted Turbines Technology”, 2016

Quote 1: “A duct surrounding the rotor captures more of the oncoming wind, directing it through the rotor to increase the amount of wind energy the rotor sees.”

Quote 2: “While a proper duct design is key a performance increase, the additional cost is even more important in evaluating the cost/kWh of the turbine.”

  1. Belloni and R.H.J. Willden (Department of Engineering Science, University of Oxford, Oxford, UK), “A computational study of a bi-directional ducted tidal turbine”, 2010

Quote 1: “Compared to the bare disc a clear increase in both thrust and power coefficient is visible for the ducted disc.”

Quote 2: “Simulation results show that the turbine’s power coefficient, defined based on the rotor swept area, can be modestly increased through the use of the duct. The increase in power coefficient is accompanied by an increase in the overall thrust acting on the device.”

  1. Ogin Energy at Oginenergy.com

Quote 1: “The Ogin Turbine is different.  Its unique shroud design takes advantage of the latest advances in the aerospace industry to change physical airflow patterns through and around the turbine.  Annual energy output per kW of rated capacity is increased by 50%, while peak energy output from the ultra-compact rotor is increased by up to three times per unit of swept area.

• AMERICAN BIRD CONSERVANCY Can Wind Energy Be Bird Safe?:

Can Wind Energy Be Bird Safe?


Nearly every week, Kimberly Kaufman receives messages from birders and conservationists alerting her to new wind energy designs that bill themselves as safe for wildlife. The technologies come in all shapes and sizes and are in varying stages of development. Yet each claims to do one thing that conventional wind turbines can’t: harness the incredible power of wind without killing birds.

Taking a Different Approach with Wind

One of the new companies is SheerWind, whose Invelox technology harvests wind energy even in areas where airflow is minimal. Invelox captures wind by funneling it through tubes that “squeeze” the wind and increase its speed, much in the same way that putting one’s finger over a garden hose will accelerate the flow of water. Then multiple turbines located inside the structure generate power from the magnified wind speed.


•BATTLE CREEK ENQUIRER: Fort Custer prepares for climate change

AUGUSTA – The Army National Guard at Fort Custer is working toward energy independence and anticipating the effects of climate change.

For at least two years the guard has been preparing a plan to use alternative energy and to look at possible consequences of changes in the environment and climate.

On Tuesday the guard provided a public look at the plan, “Adaptation Planning for Climate Resilience,”  a Michigan Army National Guard pilot project.

During a series of meetings, the guard is attempting to look at long-term energy alternatives, recycling, and how it might respond to effects of climate change, according to Brig. Gen. Mike Stone, the Michigan National Guard assistant adjutant general for installations.

Stone told about 15 people attending the session Tuesday morning at Fort Custer that the guard is looking for ways to preserve resources and save money. “It is the right thing to do and it makes good business sense,” he said. Two of the most visible initiatives are a wind funnel designed to capture and increase air flow to turbine-generators and an adjacent field of solar panels.


•GREENPEACE: 9 craziest examples of wind power

Wind power is clean, reliable, infinite and an affordable alternative to fossil fuels. But not only that, wind energy is special and innovative! Our selection of nine miraculous wind turbines and wind farms from around the world proves that.

Wind Horn on US military base and Dutch polder

The wind horn at the US Army base. Photo: Sheer Wind

This 30 meter high horn is on a military base in the US state of Michigan . The wind flows through high openings inward. Turbines that are in the horn drafted generate energy. In the horn accelerates the flow, which at low wind speeds electricity can be generated.

The second church worldwide is applying the technology in the Netherlands. The municipality Goeree – Overflakkee launch a pilot project for five years. The test should show whether the technology is future-proof.







•CLEANTECH CONCEPTS: Wind Harvesting Funnel Takes On Turbines

When it comes to harnessing wind for energy, Dr. Daryoush Allaei, a Purdue-trained Minnesota engineer and founder of SheerWind, thinks the industry is looking at the problem the wrong way. Current wind turbines are really only an optimized step beyond the old sail based windmills of Europe, passively waiting for the appropriate wind.

Instead, if the objective is power from wind, why not accelerate the wind for use in areas where turbines won’t work? Additionally, since conventional wind turbines kill approximately 573,000 birds annually, according to a 2015 Wildlife Society bulletin, it would be helpful to make them safer and usable in bird-filled areas like shorelines.

SheerWind’s technology is a cost-effective, high-performance alternative to conventional wind technology. By capturing, accelerating, and harvesting wind power in a funnel system called INVELOX, it turns traditional wind power systems upside down by first using a funnel to collect the wind, channeling that wind to increase its speed, and then delivering it efficiently to multiple turbines safely housed at ground level. It enables energy to be produced from very low wind speeds of 2 meters per second, in locations close to an end user — even on rooftops in urban areas —and eliminates the need for complex power and grid systems. Because the system is enclosed, it is bird-safe.


• CADDIGEST: Strange-Looking Contraption Is Actually a Wind Turbine

Renewable energy can come from the strangest places—and can be harvested in some of the most unique ways. This is truly evident in the recent launch of a somewhat Seussian-like wind generation station.

Generation Through Concentration and Acceleration

The funnel system—called INVELOX—harnesses incoming wind by channeling it through a funnel design that concentrates and accelerates the wind motion.

An illustration demonstrates how the wind power is concentrated throughout the system. (Image courtesy of SheerWind.)

An illustration demonstrates how the wind power is concentrated throughout the system. (Image courtesy of SheerWind.)

SheerWind states that this design allows for wind to be captured at speeds as low as 2 meters per second—and that it is structurally compatible enough to be built on urban rooftops.

According to an April 2016 report, the INVELOX can increase wind speeds by 7 to 12 times and create winds as high as 75 meters per second.  READ MORE






• NORTH AMERICAN WINDPOWER: Wind Funnel Technology to South Dakota

SheerWind Brings Wind Funnel Technology To South Dakota

Through a new licensing agreement with Mark Luke Wind Energy LLC, Minnesota-based SheerWind’s wind power generating systems will now be marketed and deployed in South Dakota.

The agreement is SheerWind’s first of its kind in the U.S. and sixth globally. Mark Luke Cos., located in Sioux Falls, S.D., is introducing SheerWind’s technology under its renewables division.

SheerWind’s multi-patented INVELOX technology (for INcreased VELocity) turns traditional wind power systems upside down by first using a funnel to collect the wind, channeling that wind to increase its speed and then delivering it efficiently to multiple turbines safely housed at ground level.  READ MORE

• SCOOP BUS: New Technology Outperforms

An overseas test has revealed a technology available to New Zealand businesses is capable of producing results three times greater than traditional systems according to Pacific Wind program manager Reza Sehdehi.

This week, energy and engineering company Pacific Wind released results of a year-long study comparing the output of INVELOX to traditional wind generation capabilities discovering that not only did the INVELOX system outperform a traditional wind turbine tower it’s performance was triple that of traditional systems.

Rather than having turbines on poles in the air INVELOX systems place the turbines on the ground, using funnels to capture and direct air towards wind turbines.

Varying pipe widths in the system accelerate the wind utilizing the Venturi effect, a phenomenon used by Dyson airplane fans to deliver either cold or hot air to targeted areas.

This allowed the unit to produce 260% more electrical energy and 300% more power than traditional systems without any of the negative effects like wind noise or flickering.

“Make no mistake, INVELOX is the future of wind power generation,” says Sehdehi.

Read more

• PACIFIC WIND: INVELOX Proves Real-World Performance

No doubt you’ve heard the phrase ‘the proof of the pudding is in the eating’. It might have first emerged in the 1920’s but it is no less true today, especially when it comes to things like technology.

Is the new technology as good as the creators say it is? Will it be up to snuff? Will it stand the rigours of the world? Is it yet another a hoax or a scam that will fail when actually put into practice?

People often seek out studies, reviews and whitepapers for good reason. They allow people to buy with the confidence that not only that new technology has no major flaws but any that minor ones have an easy solution as well.

INVELOX Review Proves Real-World Performance

• THE LAND Technology brings wind power closer to home

CHASKA, Minn. — The winds of change of renewable energy are blowing and a Chaska company is harnessing wind to provide electrical power on a large and small scale. Since 2010, SheerWind has been developing a wind-operated electrical generator which is not only compact, but requires less wind to operate.

As opposed to the towering wind turbines found dotting the countryside with their enormous propellers, SheerWind’s INVELOX system can be utilized at a variety of locations and customized to fill the clients’ needs.

In its basic form, the INVELOX system consists of a tower which captures the wind and directs it down a tapered chute, through a turbine and out (see example).

Read more