China
Africa
Explore chapters and articles related to this topic
Small-scale wind power energy systems for use in agriculture and similar applications
Published in Jochen Bundschuh, Guangnan Chen, D. Chandrasekharam, Janusz Piechocki, Geothermal, Wind and Solar Energy Applications in Agriculture and Aquaculture, 2017
Wojciech Miąskowski, Krzysztof Nalepa, Paweł Pietkiewicz, Janusz Piechocki
In some solutions, the blade pitch angle can be modified with the use of a hydraulic actuator. The rotor is mounted on a low-speed shaft which transmits power to a high-speed shaft via a gearbox. The high-speed shaft is coupled with the generator shaft. Some wind towers operate without a gearbox. The standard rotor speed is 10–50 revolutions per minute (rpm), and the gearbox increases rotor speed to 1500–3000 rpm (Hansen, 2015).
Engine performance
Published in Mohammad H. Sadraey, Aircraft Performance, 2017
The purpose of a variable pitch is to maintain an optimal angle of attack (maximum lift to drag ratio) on the propeller blades as aircraft speed varies. Early pitch control systems were pilot-operated, either two-position or manually variable. The pitch of the propeller may be controlled in flight to provide improved performance in each phase of flight. Following World War II, automatic propellers were developed to maintain an optimum angle of attack (best efficiency). This is usually done via a mechanical governor that continually adjusts the blade pitch angle. This feature of a variable-pitch propeller will provide the pilot with performance advantages, including shorter takeoff run, improved climb performance, improved fuel efficiency, greater range, higher maximum speed, steeper descent, and shorter landing run. At low speed (e.g., takeoff), the prop has the highest pitch angle, while at high speed (e.g., cruise), the prop has the lowest pitch angle.
Genesis
Published in Henry H. Perritt, Eliot O. Sprague, Domesticating Drones, 2016
Henry H. Perritt, Eliot O. Sprague
He finally realized that his failure to design an effective cyclic control resulted from a failure to understand gyroscopic effects. The cyclic control on a helicopter changes blade pitch asymmetrically, as the rotor turns. When he changed the phase of applying asymmetric pitch changes to the main rotor by advancing them 90 degrees, the cyclic control worked. By 1942, the armed services, the public, and a variety of commercial entities were growing excited about the helicopter’s potential.
Application of artificial intelligent technique to maximize power yielding ability of wind turbine
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2022
Endalew Ayenew, Milkias Berhanu
Power-yielding capacity is the foremost performance of wind turbines. Variable-speed and variable-pitch horizontal axis wind turbines have a good capacity of power capturing from the wind and become more in use recently. Variation in wind speed is the key factor that affects wind energy harvesting. Accordingly, wind turbine blade pitch angle is tuned to limit turbine rotor speed and thus the output power to the rated value. To harvest maximum energy from the kinetic energy of the wind, blade aerodynamic is improved that minimizes wake effect and reduces aerodynamic drag losses (Editor David 2009; Ragheb 2013).