Results 231 to 240 of about 63,753 (279)

Rotor Performance of a Full-Scale Heated Tail Rotor

Proceedings of the Vertical Flight Society 71st Annual Forum, 2015
A CFD approach using the NASA OVERFLOW code to predict the impact of ice accretion on a Bell 206 tail rotor is evaluated. The basis for the computational study is a test, conducted at the NASA Glenn Icing Research Wind Tunnel. The test acquired thrust and power measurements before, during, and after various ice accretion and blade heating ...
Jason Wright, Robert Narducci, Roger Aubert   +2 more
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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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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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