Source 1:
Mohamed A. El-Sharkawi, “Renewable Energy”, in Electric Energy: An Introduction, 3rd Ed.Boca Raton, CRC Press, 2013, ch. 6, sec. 2. pp. 133-157.
The majority of modern wind turbine designs are comprised of three rotary blades connected to a central, rotating axis. The blades are shaped as airfoils such as to produce a pressure differential either side of the blade, resulting in a force and therefore torque existing along the length of the blade. These turbines are constrained by the Betz Limit, which states that a wind can capture at most 59% of the available wind energy. At high wind speeds, the blades must be feathered to ensure safe operation. The electrical power is generated by a 3 phase AC generator in which the central axis rotates.
Source 2:
Mohamed A. El-Sharkawi, “Renewable Energy”, in Electric Energy: An Introduction, 3rd Ed.Boca Raton, CRC Press, 2013, ch. 6, sec. 3. pp. 158-165.
Unlike wind power turbines, hydro-kinetic generators operate through pressure differentials and are not affected by the limitations of the Betz Limit. This is due to the potential energy of the pent up water becoming zero at the earth’s surface and the fact that the mass and pressure of the water is responsible for turning the turbine. The turbine blades turn with the moving water around a central axis, causing rotary motion which is converted to electrical power by a generator.
Source 3:
Tuan C. Nguyen. (2014, June). Is this odd-looking wind turbine the most efficient you can buy? [Online]. Available: http://www.washingtonpost.com
A blade less wind turbine, the Archimedes screw turbine represents a high efficiency alternative to traditional blade designs. According to reports, these turbines can generate up to 80% of the Betz Limit, indicating efficiencies on par with the most advanced blade turbines available.Because of their design, minimal resistance is encountered by the wind, and therefore minimal noise and vibration is produced. This makes them ideal for crowded urban environments.
Source 4:
Vincent Domenic Romanin. Theory and Performance of Tesla Turbines [Online]. AvailableFTP: escholarship.org/uc/item/6584x24x#page-1
A unique type of turbine, the Tesla Turbine relies on laminar flow of a gas or liquid to produce drag across several layers of very smooth and thin disks. As the gas or liquid flows into the turbine, it is attracted to the center holes of the turbine which act as a type of exhaust port.However, as it flows toward the central holes, drag is produced on the disks, causing rotary motion. This motion produces centripetal force, forcing the gas or liquid to flow across the entire surface of the disk, resulting in increased drag area and therefore greater efficiencies. This turbine also is unaffected by the classical limitations set by the Betz limit.
Source 5:
Gundtoft, Søren. "Wind Turbines." 2nd ed. 1 (2009): 1-37. University College of Aarhus, June 2009. Web. Feb. 2017.
The design of the turbine blades required theory of blade geometry and turbine blade configuration. This paper discusses the theory behind turbines and their efficiencies. Turbine power calculations were carried out with the help of this paper.
Source 6:
Schubel, Peter J., and Richard J. Crossley. "Wind Turbine Blade Design." Energies (2012): 1-25. 6 Sept. 2012. Web. Feb. 2017.
This paper was used in conjunction with "Wind Turbines" by Gundtoft for the development of the turbine designed in this project. Additional blade geometry calculations were carried out with the theory described in this paper.