Results 181 to 190 of about 7,948 (233)
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The Journal of the Helicopter Association of Great Britain, 1948
Ladies and Gentlemen,It is with pleasure that I introduce to you today MR MCCLEMENTS, who is going to talk to us on the subject of “Helicopter Rotors”MR McCLEMENTS is a relatively newcomer to the rotary wing industry and only claims a modest two years or so of direct connection, first with the Ministry of Supply and now as experimental engineer to the ...
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Ladies and Gentlemen,It is with pleasure that I introduce to you today MR MCCLEMENTS, who is going to talk to us on the subject of “Helicopter Rotors”MR McCLEMENTS is a relatively newcomer to the rotary wing industry and only claims a modest two years or so of direct connection, first with the Ministry of Supply and now as experimental engineer to the ...
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2001
This effort was directed toward demonstration of the efficacy of a concept for mitigation of the rotor blade modulation problem in helicopter communications. An antenna is envisioned with radiating elements mounted on the rotor and rotating with it. The rf signals are coupled to the radio stationary with respect to the airframe via a coupler of unique ...
Vaughn P. Cable, Ronald J. Pogorzelski
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This effort was directed toward demonstration of the efficacy of a concept for mitigation of the rotor blade modulation problem in helicopter communications. An antenna is envisioned with radiating elements mounted on the rotor and rotating with it. The rf signals are coupled to the radio stationary with respect to the airframe via a coupler of unique ...
Vaughn P. Cable, Ronald J. Pogorzelski
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Maneuvers for a Quad-Rotor Autonomous Helicopter
AIAA Infotech@Aerospace 2007 Conference and Exhibit, 2007The objective of this paper is to generate a desired flight path to be followed by an autonomous quad-rotor helicopter. The novel approach consists in the explicit formulation of both under-actuation constraints, as there is 6 degrees of freedom and only 4 inputs. A simple but efficient method of trajectory generation is proposed.
Bestaoui, Yasmina, Slim, Rajia
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2017
The theory discussed in previous chapters is now applied to a helicopter rotor. The results are matched with published literature. A MATLAB code is given along with this book which can be used to generate results given in this chapter.
Ranjan Ganguli, Vijay Panchore
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The theory discussed in previous chapters is now applied to a helicopter rotor. The results are matched with published literature. A MATLAB code is given along with this book which can be used to generate results given in this chapter.
Ranjan Ganguli, Vijay Panchore
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Modeling and Stabilization of a Multi-Rotor Helicopter
Journal of Intelligent & Robotic Systems, 2012In this paper, a nonlinear control augmented system for a novel eight rotor helicopter is developed, in order to achieve hover flight. Simulation results underline the good performance of the proposed control strategy. Experimental tests have been performed showing the reliability of the proposed approach.
Alejandro Sámano +3 more
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Aerodynamics and aeroacoustics of helicopter main-rotor/tail-rotor interaction
5th AIAA/CEAS Aeroacoustics Conference and Exhibit, 1999Preliminary results from an ongoing effort to model the interaction aerodynamics and aeroacoustics of main- and tail rotor of a helicopter in subsonic flow are presented. The configurations studied are a) a two-blade main- and tail rotor in hover, and b) a four-blade main- and a two-blade tail rotor in climb flight.
Ahmed, S.R., Yin, J.
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A theoretical study of helicopter rotor noise
Journal of Sound and Vibration, 1969Abstract A comprehensive theoretical study of the problem of helicopter rotor noise radiation is presented. The theory includes blade slap, rotation noise and vortex noise effects. Peak spectral levels over the “vortex noise” region are shown to be due to the higher harmonics of the rotational noise.
M. V. Lowson, J. B. Ollerhead
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10th Aeroacoustics Conference, 1986
A study was made of helicopter tail rotor noise, particularly that due to interactions with the main rotor tip vortices, and with the fuselage separation mean wake. The tail rotor blade-main rotor tip vortex interaction is modelled as an airfoil of infinite span cutting through a moving vortex.
S.-T. CHOU, A. GEORGE
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A study was made of helicopter tail rotor noise, particularly that due to interactions with the main rotor tip vortices, and with the fuselage separation mean wake. The tail rotor blade-main rotor tip vortex interaction is modelled as an airfoil of infinite span cutting through a moving vortex.
S.-T. CHOU, A. GEORGE
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Actuator disc modelling for helicopter rotors
Aerospace Science and Technology, 2004Summary: The helicopter project CHANCE contains, among other developments, the quasi-steady approximation to modelling rotors with actuator discs. This reduces the cost of an unsteady simulation down to a stationary one. In testing existing approaches in the literature, the source term implementation proved to perform best, especially in forward flight:
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1973
The development of fiber reinforced resin-bonded structural composite materials has created a new degree of design flexibility for the helicopter engineer. The development and commercial availability of glass fibers, carbon or graphite fibers, and boron fibers, with their attendant widely varying stiffness properties and material densities, enable the ...
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The development of fiber reinforced resin-bonded structural composite materials has created a new degree of design flexibility for the helicopter engineer. The development and commercial availability of glass fibers, carbon or graphite fibers, and boron fibers, with their attendant widely varying stiffness properties and material densities, enable the ...
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