Results 61 to 70 of about 30,459 (234)
Energy Science &Engineering, Volume 13, Issue 11, Page 5432-5450, November 2025.The increasing demand for energy in daily life and the finite nature of fossil fuel reserves have driven researchers worldwide to explore renewable energy sources such as wind energy. To optimize the performance and minimize energy losses in vertical wind turbines, parameters such as the airfoil's angle of attack, as well as the horizontal and vertical
Reza Abbaspour +2 more
wiley +1 more source
Dynamic Stall Characteristics of Thick Wind Turbine Airfoils
Wind Energy, Volume 28, Issue 11, November 2025.ABSTRACT This paper studies the dynamic stall characteristics of thick flatback and nonflatback wind turbine airfoils. Two airfoils with a maximum thickness of 35%$$ 35\% $$ were studied, with trailing edge thicknesses of 2%$$ 2\% $$ and 10%$$ 10\% $$, respectively.
Mehdi Doosttalab +4 more
wiley +1 more source
Jixie chuandong, 2018 For unmanned helicopter economic cruises,main rotor speed changes could be significant. At present,the most effective method of changing the main rotor speed associated with the great speed range and low cost is a variable speed gear transmission ...
Li Zhengminqing +4 more
doaj
Helicopter rotor trailing edge noise
7th Aeroacoustics Conference, 1981 A two dimensional section of a helicopter main rotor blade was tested in an acoustic wind tunnel at close to full-scale Reynolds numbers to obtain boundary layer data and acoustic data for use in developing an acoustic scaling law and testing a first principles trailing edge noise theory. Results were extended to the rotating frame coordinate system to
R. SCHLINKER, R. AMIET
openaire +2 more sources
Performance Improvement of Variable Speed Rotors by Gurney Flaps [PDF]
, 2017 Gurney flaps are used for improving the performance of variable speed rotors. An analytical model able to predict helicopter rotor power is first presented, and the flight data of the UH-60A helicopter is used for validation. The predictions of the rotor
Barakos, George N., Dong, Chen, Han, Don
core +2 more sources
The Effect of Rotor Size on the Teeter Behavior of Two‐Bladed Wind Turbines
Wind Energy, Volume 28, Issue 11, November 2025.ABSTRACT The rotor of a two‐bladed turbine allows the implementation of an additional degree of freedom around the rotating hub y‐axis. This idea is over 60 years old, and various research and commercial turbines have had a teeter hinge. Fatigue and extreme loads can be reduced significantly with a teeter hinge. Teetered turbines have been mainly below
Fabian Bölle né Anstock +1 more
wiley +1 more source
Xibei Gongye Daxue Xuebao, 2019 This paper studies helicopter optimal landing and control procedure after tail rotor control failure (TRCF) in different collective pitch. The optimal control problem of landing after tail rotor control failure was solved numerically by direct multiple ...
doaj +1 more source
Polymer Composites, Volume 46, Issue S1, Page S9-S25, 10 September 2025.Typical manufacturing defects and mitigation strategies in thick thermosetting composites. Abstract The composite part industry is currently dominated by thin‐section geometries. However, thick composites gain interest in many applications where monolithic parts are required, such as foils, wind mill root blades, and so forth.
Francesco Taddei +2 more
wiley +1 more source
An investigation of coupling ship/rotor flowfield using steady and unsteady rotor methods
Engineering Applications of Computational Fluid Mechanics, 2017 A coupling numerical methodology has been developed using the Navier–Stokes solver for ship/rotor flowfield simulation during the helicopter shipboard launch.
Yongjie Shi, Yi Xu, Kun Zong, Guohua Xu
doaj +1 more source
Design and Physical Prototyping of a Novel Braking System for a Helicopter Rotor
Designs, 2019 The aim of this paper was to demonstrate the improved functionality and performance of an electromechanical brake for a helicopter main rotor, which to date has been hydraulically actuated using a disc brake and caliper arrangement.
Julian D. Booker +2 more
doaj +1 more source