Results 221 to 230 of about 22,232 (271)
Aerodynamics and aeroacoustics of helicopter main-rotor/tail-rotor interaction [PDF]
5th AIAA/CEAS Aeroacoustics Conference and Exhibit, 1999 Preliminary results from an ongoing effort to model the interaction aerodynamics and aeroacoustics of main- and tail rotor of a helicopter in subsonic flow are presented. The configurations studied are a) a two-blade main- and tail rotor in hover, and b) a four-blade main- and a two-blade tail rotor in climb flight.
Ahmed, S.R., Yin, J.
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Electric powertrain for helicopter tail rotor [PDF]
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 +2 more
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Effect of tail-rotor torque variation on vibration at helicopter tail-rotor drive-train
2018 IEEE Aerospace Conference, 2018Condition monitoring and fault diagnostics in rotorcraft have significant effect on improving safety level and reducing operational and maintenance costs. Most of the commercially available diagnostic tools for rotating machinery are based on vibration analysis.
Michael R. Habib +2 more
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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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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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10th Aeroacoustics Conference, 1986
A study was made of helicopter tail rotor noise, particularly that due to interactions with the main rotor tip vortices, and with the fuselage separation mean wake. The tail rotor blade-main rotor tip vortex interaction is modelled as an airfoil of infinite span cutting through a moving vortex.
S.-T. CHOU, A. GEORGE
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A study was made of helicopter tail rotor noise, particularly that due to interactions with the main rotor tip vortices, and with the fuselage separation mean wake. The tail rotor blade-main rotor tip vortex interaction is modelled as an airfoil of infinite span cutting through a moving vortex.
S.-T. CHOU, A. GEORGE
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Rotor Performance of a Full-Scale Heated Tail Rotor
Proceedings of the Vertical Flight Society 71st Annual Forum and Technology Display, 2015A 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 cycles and ...
Jason Wright +2 more
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The Flapping Propulsion Rotor - Single Rotor without Tail Rotor [PDF]
, 2012 The term “Flapping Propulsion Rotor” has first been used by H.G. Küssner in Germany in the 30ies of the last century. Based on a patent, Küssner has developed a wind tunnel model to demonstrate his concept of a rotor with a tip path plane tilted against ...
Geißler, Wolfgang +1 more
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A simulation model for tail rotor failure
Astrodynamics Conference, 1992Tail 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, 2007AbstractThe 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, 1976The 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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