Results 211 to 220 of about 21,200 (250)

Divergent Vibration in Helicopter Tail Rotors

SAE Technical Paper Series, 1965
<div class="htmlview paragraph">Helicopter tail rotors are subject to many types of divergent vibration. A classification of these various types is presented, and a description given of those which have been actually observed. The means used by manufacturers to predict and avoid such vibrations include various calculations in the design stage and
openaire   +1 more source

Bearingless Tail Rotor Loads and Stability

1977
Abstract : Four wind tunnel model tests were conducted on a model flex-strap bearingless tail rotor was studied for aeroelastic stability characteristics and loads. In all, 12 individual rotor parameters were investigated to determine their effect on aeroelastic stability.
W. Miao, W. T. Edwards
openaire   +1 more source

Orthogonal Blade-Vortex Interaction on a Helicopter Tail Rotor

AIAA Journal, 2008
The orthogonal blade-vortex interaction has been simulated using unsteady Reynolds-averaged Navier-Stokes equations with turbulence closure equations. The cases investigated are relative to an interaction between a lifting blade at a high angle of attack and an orthogonal vortex that travels either head-on or at 45 deg to the leading edge.
Filippone, Antonio; id_orcid 0000-0002-6512-6566, Afgan, Imran; id_orcid 0000-0002-8082-299X   +1 more
openaire   +2 more sources

Rotor Wake Study Near the Horizontal Tail of a T-Tail Configuration

Journal of Aircraft, 2002
Development of advanced rotorcraft configurations has highlighted a need for high-quality experimental data to support the development of robust and accurate analytical design tools. To provide high-quality experimental data, a test program was conducted in the NASA Langley Research Center 14- by 22-Foot Subsonic Tunnel to measure the flow near the ...
Susan Althoff Gorton, John D. Berry, W. Todd Hodges, Deane G. Reis   +3 more
openaire   +1 more source

A Comparative Study of Tail Rotor Noise Mechanisms

Journal of the American Helicopter Society, 1986
A study was made of helicopter tail rotor noise, particularly that due to interactions with the wakes of the main rotor, hub, and fuselage, and with the engine exhaust. Both harmonic and broadband noise were analyzed. The disturbed flow into the tail rotor was modeled using combinations of aerodynamic and acoustic flow codes along with some necessary ...
A. R. George, S. ‐T. Chou
openaire   +1 more source

Cracking in a Tail Rotor Blade in a Helicopter

2005
Abstract The tail rotor blade of a helicopter developed a visible crack during service. The cracked region was removed from the blade and the fracture surface was examined in a SEM, revealing shallow pitting on the inside surface of the skin and a corresponding reduction in thickness. Based on these findings, investigators concluded that
openaire   +1 more source

Method for the Extraction of Helicopter Main and Tail Rotor Noise

Journal of Aircraft, 2018
In this paper a method for the extraction of main and tail rotor noise from an acoustic pressure time history of a helicopter is described.
openaire   +2 more sources

Aeroacoustic investigation of a ducted tail rotor

AIAA AVIATION 2023 Forum, 2023
Prateek Jaiswal, Jose Rendon, Yann Pasco, Marlène Sanjosé, Stephane Moreau   +4 more
openaire   +1 more source

Description of a Dynamical Framework to Analyse the Helicopter Tail Rotor

Dynamics, 2021
Salvador Castillo-Rivera, Maria Tomas-Rodriguez   +1 more
exaly  

Tail Rotor Performance in Presence of Main Rotor, Ground, and Winds

Journal of the American Helicopter Society, 1974
Wayne Wiesner, Gary Kohler
openaire   +1 more source