Results 91 to 100 of about 30,707 (232)
Helicopter low-speed yaw control [PDF]
, 1993 A system for improving yaw control at low speeds consists of one strake placed on the upper portion of the fuselage facing the retreating rotor blade and another strake placed on the lower portion of the fuselage facing the advancing rotor blade.
Crowell, Cynthia A. +2 more
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Coupled flight dynamics and CFD - demonstration for helicopters in shipborne environment [PDF]
, 2017 The development of high-performance computing and computational fluid dynamics methods have evolved to the point where it is possible to simulate complete helicopter configurations with good accuracy.
Barakos, G.N., Crozon, C., Steijl, R.
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Study on dynamic characteristics of the helicopter main transmission system
Jixie chuandongObjectiveTo identify the main excitation frequencies that cause the vibration of the helicopter main transmission system and reveal the influence of system speed, rotor torque, and rotor lift on the dynamic characteristics of the helicopter main ...
XU Huachao +5 more
doaj
An investigation of rotor harmonic noise by the use of small scale wind tunnel models [PDF]
Noise measurements of small scale helicopter rotor models were compared with noise measurements of full scale helicopters to determine what information about the full scale helicopters could be derived from noise measurements of small scale helicopter ...
Schaffer, E. G., Sternfeld, H., Jr.
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Lifting surface theory for a helicopter rotor in forward flight [PDF]
, 1984 A lifting surface theory was developed for a helicopter rotor in forward flight for compressible and incompressible flow. The method utilizes the concept of the linearized acceleration potential and makes use of the vortex lattice procedure. Calculations
Runyan, H. L., Tai, H.
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INTERFERENCE BETWEEN HELICOPTER AND ITS SURROUNDINGS, EXPERIMENTAL AND NUMERICAL ANALYSIS
TASK Quarterly, 2009 The paper describes the phenomenon of the occurrence of aerodynamic interference between a helicopter and an object in its near vicinity. Such situations occur during rescue missions as well as during police and military operations when the helicopter ...
TOMASZ ŁUSIAK +2 more
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Research of the crosswind effect on the single-rotor helicopter unintentional yaw rotation
Научный вестник МГТУ ГАDuring the operation of single-rotor helicopters, aviation accidents quite frequently occur in the form of an unintentional turn or even a yaw rotation, causing, as a rule, a ground collision.
V. V. Efimov +2 more
doaj +1 more source
Reduction of high-speed impulsive noise by blade planform modification of a model helicopter rotor [PDF]
The reduction of high speed impulsive noise for the UH-1H helicopter was investigated by using an advanced main rotor system. The advanced rotor system had a tapered blade planform compared with the rectangular planform of the standard rotor system ...
Conner, D. A., Hoad, D. R.
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Study for prediction of rotor/wake/fuselage interference, part 1 [PDF]
A method was developed which allows the fully coupled calculation of fuselage and rotor airloads for typical helicopter configurations in forward flight. To do this, an iterative solution is carried out based on a conventional panel representation of the
Clark, D. R., Maskew, B.
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AerospaceActive rotors with trailing-edge flaps (TEFs) are a promising method applied to the main-rotor blades of the helicopter for vibration suppression. For active rotors, both the TEF actuator and the corresponding deflection control law determine their ...
Xiancheng Gu +3 more
doaj +1 more source