Results 71 to 80 of about 30,676 (232)
Helicopter far-field acoustic levels as a function of reduced main-rotor advancing blade-tip Mach number [PDF]
During the design of a helicopter, the weight, engine, rotor speed, and rotor geometry are given significant attention when considering the specific operations for which the helicopter will be used. However, the noise radiated from the helicopter and its
Lemasurier, Philip +2 more
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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
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 ...
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CAA Modeling of Helicopter Main Rotor in Hover [PDF]
, 2017 In this work rotor aeroacoustics in hover is considered. Farfield observers are used and the nearfield flow parameters are obtained using the in house HMB and commercial Fluent CFD codes (identical hexa-grids are used for both solvers). Farfield noise at
Barakos, George +5 more
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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
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
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The UH-1H helicopter icing flight test program: An overview [PDF]
An ongoing joint NASA/Army program to study the effects of ice accretion on unprotected helicopter rotor aerodynamic performance is discussed. This program integrates flight testing, wind tunnel testing, and analytical modeling. Results are discussed for
Richter, G. P., Shaw, R. J.
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RESULTS OF THE FIRST MI-171A2 FLYING LABORATORY TEST PHASE
Научный вестник МГТУ ГА, 2016 The present publication describes the results of the first stage of the flying laboratory (Mi-171 helicopter) flight tests performed at Mil Moscow Helicopter Plant, JSC facilities. Main rotor components with blades made of polymer composite materials and
V. A. Ivchin, K. Y. Samsonov
doaj
Rotorcraft research testing in the National Full-Scale Aerodynamics Complex at NASA Ames Research Center [PDF]
The unique capabilities of the National Full-Scale Aerodynamics Complex (NFAC) for testing rotorcraft systems are described. The test facilities include the 40- by 80-Foot Wind Tunnel, the 80- by 120-Foot Wind Tunnel, and the Outdoor Aerodynamic Research
Johnson, W., Smith, C. A., Warmbrodt, W.
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Sand Erosion Resistance and Failure Mechanism of Polyurethane Film on Helicopter Rotor Blades. [PDF]
Polymers (Basel), 2023 Zheng L, Fan J, Gong Q, Sun W, Jia X.
europepmc +1 more source