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.
- 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.”
- 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.”
- 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.”
- 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.”
- 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.”
- 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.”
- 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.”
- 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.”