Results 241 to 250 of about 64,082 (287)

A simulation model for tail rotor failure

Astrodynamics Conference, 1992
Tail rotor failure in a helicopter can be a very dangerous and unstable condition. For this reason a helicopter simulation model, DYN, has been formulated to analyze helicopter flight response to tail rotor failure and steady flight recovery. This model uses classical rotor theory and integrates the nonlinear Euler equations of motion.
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Modelling the interaction of helicopter main rotor and tail rotor wakes

The Aeronautical Journal, 2007
AbstractThe mutual interaction between the main rotor and tail rotor wakes is central to some of the most problematic dynamic phenomena experienced by helicopters. Yet achieving the ability to model the growth and propagation of helicopter rotor wakes with sufficient realism to capture the details of this interaction has been a significant challenge to
T. M. Fletcher, R. E. Brown
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Designing to Survive Tail Rotor Loss

Journal of the American Helicopter Society, 1976
The development and application of a mathematical model for predicting sideslip during flight without a tail rotor are described in this paper. This method of analysis can he used to properly size a fin which will have sufficient static and dynamic stability to provide “fly‐back” capability if the tail rotor is lost, is damaged, or fails.
Terri J. Horst, Robert J. Reschak
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Electric powertrain for helicopter tail rotor

2016 6th International Electric Drives Production Conference (EDPC), 2016
The design of multi-phase permanent magnet brushless motor for an electrical helicopter tail rotor is introduced and described. The presented electric machine allows a substitution of the actual mechanisms in tail rotor system matching envelope, weights and performances. In order to obtain high torque with small overall dimensions of the motor, a spoke-
Castellini, Luca, D'andrea, Moreno, Villani, Marco   +2 more
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Lynx Main Rotor/Tail Rotor Interactions: Mechanisms and Modelling

Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering, 1994
A flight trial has been conducted by the Defence Research Agency (DRA) Bedford using a Lynx AH Mk5 helicopter fitted with an instrumented tail rotor to collect data on tail rotor aerodynamic performance. The analysis carried out to date has concentrated on the effects of main rotor wake interactions on the tail rotor.
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Tail Rotor Flapping

1999
Abstract : There was a letter in Feedback, September 1999 issue of Rotor & Wing entitled "Go-No-Go" from James D. Thomas, Jr. of Charleston, WV. The following description addresses my involvement with a Tail Rotor Flapping problem with the SH-3 Helicopter, now long since solved.
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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
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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
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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
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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
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