Results 11 to 20 of about 231,082 (310)
Variable-speed tail rotors for helicopters with variable-speed main rotors [PDF]
The Aeronautical Journal, 2017 ABSTRACTVariable tail rotor speed is investigated as a method for reducing tail rotor power, and improving helicopter performance. A helicopter model able to predict the main rotor and tail rotor powers is presented, and the flight test data of the UH-60A helicopter is used for validation. The predictions of the main and tail rotor powers are generally
Han, D., Barakos, G.N.
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Aeroacoustic analysis of main rotor and tail rotor interaction [PDF]
, 2008 The increased restrictions placed on helicopter noise levels over recent decades have encouraged\ud manufacturers to better understand tail rotor noise and its aerodynamic sources. A\ud generic single main rotor and tail rotor helicopter has been simulated in high speed forward,\ud and quartering, flight using the Vorticity Transport Model.
Fletcher, T.M. +2 more
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CAA modeling of helicopter main rotor in hover [PDF]
EPJ Web of Conferences, 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
Kusyumov Alexander N. +4 more
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Авіаційно-космічна техніка та технологія, 2021 Under certain conditions of a helicopter flight, the main rotor can exert a rather strong effect on the tail rotor, changing its traction and power characteristics.
Михайло Юрійович Кибальний +3 more
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Configuration Study of Electric Helicopters for Urban Air Mobility
Aerospace, 2021 There is currently interest in the design of small electric vertical take-off and landing aircraft to alleviate ground traffic and congestion in major urban areas.
Julia A. Cole +4 more
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Modelling of Flow Characteristics of Main Rotor with Elliptical Root Section in Hover Mode [PDF]
E3S Web of Conferences, 2023 The modelling of a helicopter main rotor flow field in hover regime is being considered. The aerodynamic and aeroacoustics characteristics of two rotor models with different blade root geometries are compared.
Kusyumov Sergey +4 more
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Научный вестник МГТУ ГА, 2018 The efficiency of the helicopter main rotor in the hover mode is very important, because this mode essentially determines the performance characteristics of the helicopter.
Y. M. Ignatkin +2 more
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Application of pressure head theory to determine the aerodynamic characteristics of the helicopter main rotor [PDF]
E3S Web of Conferences, 2021 A method is proposed for calculating main aerodynamic characteristics of the main rotor of the Mi-26 helicopter: a lift, a reactive moment, a required power of the propulsion system, a speed of the inductive air flow, a throttle response coefficient, a ...
Reshenkin Andrey +3 more
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Research on Calculation Method for Acoustic Scattering of Helicopter Noise
Xibei Gongye Daxue Xuebao, 2020 A new calculation method of helicopter rotor/fuselage acoustic scattering is developed. Firstly, a CFD analysis model is developed to simulate flow field of the rotor, which is based on the motional embedded grid system and RANS equations, and provides ...
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Rotor Flux Controller for Induction Machines Considering Main Inductance Saturation [PDF]
Problems of the Regional Energetics, 2020 This paper discusses the problem of controlling electromechanical systems with maximum per-formance while maintaining accuracy and minimum power consumption.
Diachenko G.
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