Results 211 to 220 of about 145,661 (263)
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Helicopter Main-Rotor/Tail-Rotor Interaction
Journal of the American Helicopter Society, 2000Preliminary results from a study to model the interaction aerodynamics and aeroacoustics of the main and tail rotor of a helicopter in subsonic flow are presented. The configurations studied are: 1) two bladed main and tail rotors in hover, and 2) a four-bladed main rotor and two-bladed tail rotor in climbing flight.
Yin, J., Ahmed, S.R.
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Entry Technology Conference, 1964
Autorotating rotors can, in a single configuration system, provide the capability for retardation, stabilization, drag force modulation, glide at useful L/D ratios, maneuvering and control during descent, and low-velocity touchdown. A given configuration will deploy over a wide range of speeds and dynamic pressures.
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Autorotating rotors can, in a single configuration system, provide the capability for retardation, stabilization, drag force modulation, glide at useful L/D ratios, maneuvering and control during descent, and low-velocity touchdown. A given configuration will deploy over a wide range of speeds and dynamic pressures.
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Reentry as an Origin for Rotors
Bulletin of Mathematical Biology, 2018The aim of the study is to understand in depth the meaning of "reentry", and to decipher if and how it can lead to malfunctions of the heart and possibly of the brain. A simple model is used to reveal the mechanism by which a single pulse of action potential rotating around a ring of excitable medium, the latter simulating a reentry circuit, can ...
Rabinovitch, A. +3 more
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On the Vibration of Rotor With Rotor/Stopper Rubbing
Volume 7A: 17th Biennial Conference on Mechanical Vibration and Noise, 1999Abstract The vibration of a flywheel rotor with rotor/stopper rubbing is investigated by experimental methods. In the experiments, the large amplitude of the rotor vibration is excited by the electromagnetic harmonic excitation force and thus causes the rubbing between the rotor and the stopper.
Xingjian Dai +2 more
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The Safety Rotor—An Electromechanical Rotor Safety System for Drones
IEEE Robotics and Automation Letters, 2018We propose a novel rotor safety mechanism for rotary-wing small unmanned aerial vehicles, such as quadrotors, that avoids problems associated with cages, rotor shrouds, and obstacle avoidance safety systems. The system works by using a passively spinning hoop as a mechanical interference sensor; changes in hoop speed are detected with a reflective IR ...
Paul E. I. Pounds, Will Deer
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Effects of rotor–rotor interaction for a small tandem rotor operating in a crosswind
Physics of FluidsThis study investigates the effects of rotor–rotor interaction on the wake and thrust characteristics of a small tandem rotor operating in a crosswind. Flow velocity and force measurements were conducted in a wind tunnel with two rotors arranged parallel to a crosswind. The results show that the rotor–rotor interaction significantly influences the wake
Seokbong Chae +4 more
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The Effects of Rotor-Rotor and Rotor-Wing Interactions on eVTOL Aeroacoustics
Proceedings of the Vertical Flight Society 79th Annual Forum and Technology Display, 2023Brendan Smith, Ullhas Hebbar, Dr. Gandhi
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Monitoring Of The Rotor Speed And Rotor Angle
1992Abstract Tachometers can be used for monitoring the angular speed of a shaft. For this purpose it is possible to use a d.c. tachometer which can be a separately excited d.c. machine. When the separately excited d.c. machine operates as a generator, and if the field current is constant, under certain assumptions its armature voltage is
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Dipolar rotor-rotor interactions in a difluorobenzene molecular rotor crystal
Physical Review B, 2006Robert D. Horansky +7 more
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