Results 91 to 100 of about 30,676 (232)
A VORTEX MODEL OF A HELICOPTER ROTOR
INCAS BULLETIN, 2009 A vortex model of a helicopter rotor is presented. Each blade of the rotor has three degrees of freedom: flapping, lagging and feathering. The motions after each degree of freedom are also known for all blades. The blade is modelled as a thin vortex surface. The wakes are free fluid surfaces.
openaire +2 more sources
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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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
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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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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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Charge control experiments on a CH-53E helicopter in a dusty environment [PDF]
Charge control tests were carried out on a ground based, Marine Corps helicopter to determine if control of the electric fields acting on the engine exhaust gases could be used to reduce the electrification of the helicopter when it operated in a dusty ...
Hunyady, S. J. +2 more
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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
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