Results 231 to 240 of about 64,260 (282)

Ice Shapes on a Tail Rotor

6th AIAA Atmospheric and Space Environments Conference, 2014
Testing of a thermally-protected helicopter rotor in the Icing Research Tunnel (IRT) was completed. Data included inter-cycle and cold blade ice shapes. Accreted ice shapes were thoroughly documented, including tracing, scanning and photographing. This was the first time this scanning capability was used outside of NASA.
Richard E. Kreeger, Jen-Ching Tsao
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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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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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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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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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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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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, Afgan, Imran
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Prediction of Main Rotor, Tail Rotor and Engine Parameters from Flight Tests

49th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference &lt;br&gt; 16th AIAA/ASME/AHS Adaptive Structures Conference&lt;br&gt; 10t, 2008
In the framework of this research project, the main rotor torque, tail rotor torque, engine torque and main rotor speed of a helicopter in forward flight are estimated by using a state space model from flight tests data. The state space model inputs are nonlinear terms made of combinations of pilot controls and helicopter states.
Michel Nadeau Beaulieu, Ruxandra Botez
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