Results 171 to 180 of about 30,707 (232)
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Technology Law and Insurance, 2000
The vital part of a helicopter is no doubt the main rotor. If the rotor fails, the helicopter will fall. Therefore rotor blades are checked very carefully and replaced or repaired if they show any indication of damage which might lead to failure. A case is reported where a rotor blade failed after a long service time without any prior indications of ...
Rolf Kieselbach, Georg Soyka
exaly +2 more sources
The vital part of a helicopter is no doubt the main rotor. If the rotor fails, the helicopter will fall. Therefore rotor blades are checked very carefully and replaced or repaired if they show any indication of damage which might lead to failure. A case is reported where a rotor blade failed after a long service time without any prior indications of ...
Rolf Kieselbach, Georg Soyka
exaly +2 more sources
Helicopter rotor thickness noise
6th Aeroacoustics Conference, 1980The attention is focused on rotor blade thickness noise (flow subsonic everywhere). The solution of the wave equation is written in a closed form (frequency domain) which emphasizes the essential parameters for this field. On another side, starting from an estimation of the loads on the rotor disk (lifting-line theory), the acoustic emission due to ...
Claude Dahan, Edmond Gratieux
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Helicopter Main-Rotor/Tail-Rotor Interaction
Journal of the American Helicopter Society, 2000Preliminary results from a study to model the interaction aerodynamics and aeroacoustics of the main and tail rotor of a helicopter in subsonic flow are presented. The configurations studied are: 1) two bladed main and tail rotors in hover, and 2) a four-bladed main rotor and two-bladed tail rotor in climbing flight.
Yin, J., Ahmed, S.R.
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On the Zero Dynamics of Helicopter Rotor Loads
European Journal of Control, 1996This paper contains some basic analysis of helicopter blade dynamics. The authors comment that many textbooks such as recent book by \textit{A. R. S. Bramwell} [Helicopter dynamics, Edward Arnold Publishers, London (1996)] are primarily concerned with stability.
Sergio Bittanti, Marco Lovera
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The Journal of the Acoustical Society of America, 1993
Flow separation behind the notch region of a swept tip of a helicopter rotor blade is reduced by features of the geometry and aerodynamic characteristics of the notch region itself. In particular it has been found beneficial for a forwardly swept leading edge portion to extend at an angle between 30 degrees and 55 degrees from a reference line parallel
Frederick J. Perry, Alan Brocklehurst
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Flow separation behind the notch region of a swept tip of a helicopter rotor blade is reduced by features of the geometry and aerodynamic characteristics of the notch region itself. In particular it has been found beneficial for a forwardly swept leading edge portion to extend at an angle between 30 degrees and 55 degrees from a reference line parallel
Frederick J. Perry, Alan Brocklehurst
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The Aeronautical Journal, 1970
To be asked to give the Lanchester Lecture, on the topic of helicopters, is a great honour and just now a wonderful chance. We all know of Lanchester's basic contributions to our knowledge of the way in which lift is generated by the creation of a vortex system.
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To be asked to give the Lanchester Lecture, on the topic of helicopters, is a great honour and just now a wonderful chance. We all know of Lanchester's basic contributions to our knowledge of the way in which lift is generated by the creation of a vortex system.
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Parallel computing for helicopter rotor design
[1993] Proceedings The 2nd International Symposium on High Performance Distributed Computing, 2002The high-speed computing (HSC) program was established in 1986 within Boeing Computer Services (BCS) to provide a prototypical environment which could be used to study the problem of integrating new computing technologies into Boeing. This paper summarizes work within the HSC program on parallel computing and concentrates on one application area ...
Joseph W. Manke +2 more
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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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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 ...
openaire +1 more source