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Helicopter rotor

About: Helicopter rotor is a research topic. Over the lifetime, 7201 publications have been published within this topic receiving 77045 citations. The topic is also known as: rotor blades & Rotor.


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05 Jun 2000
TL;DR: A history of helicopter flight can be found in this paper, where the basic helicopter aerodynamic properties are discussed and a detailed analysis of the rotor blade motion is presented, as well as a detailed discussion of the rotor wakes and tip vortices.
Abstract: Preface Acknowledgements List of main symbols List of figures List of tables 1. Introduction: a history of helicopter flight 2. Fundamentals of rotor aerodynamics 3. Blade element analysis 4. Rotating blade motion 5. Basic helicopter performance 6. Conceptual design of helicopters 7. Rotor airfoil aerodynamics 8. Unsteady aerodynamics 9. Dynamic stall 10. Rotor wakes and tip vortices Appendix Index.

2,146 citations

01 Jan 1980
TL;DR: In this paper, a benchmark test to aid the development of various rotor performance codes was conducted, where simultaneous blade pressure measurements and tip vortex surveys were made for a wide range of tip Mach numbers including the transonic flow regime.
Abstract: A benchmark test to aid the development of various rotor performance codes was conducted. Simultaneous blade pressure measurements and tip vortex surveys were made for a wide range of tip Mach numbers including the transonic flow regime. The measured tip vortex strength and geometry permit effective blade loading predictions when used as input to a prescribed wake lifting surface code. It is also shown that with proper inflow and boundary layer modeling, the supercritical flow regime can be accurately predicted.

420 citations

Journal ArticleDOI
TL;DR: In this paper, the authors apply modern nonlinear control theory to a 5-ft diameter main rotor helicopter to improve the performance of the controller and enable the tracking of aggressive trajectories.
Abstract: F light control of unmanned helicopters is an area that poses interesting problems for control researchers. The classical control strategy for helicopters assumes a linear model obtained for a particular operating point. Applying modern nonlinear control theory can improve the performance of the controller and enable the tracking of aggressive trajectories, as demonstrated in [1] for a 5-ft diameter main rotor helicopter. Civil and military applications of autonomous flying vehicles have been steadily increasing over the last few years. Traffic surveillance, air pollution monitoring, area mapping, agricultural applications, and remote inspection require high maneuverability and robustness with respect to disturbances. Since rotary wing vehicles can take off and land in limited spaces and hover above targets, these vehicles have certain advantages over conventional fixed-wing aircraft for surveillance and inspection tasks. © DIGITAL VISION Experimental implementation of linear and nonlinear control laws

371 citations

Journal ArticleDOI
TL;DR: In this article, wind tunnel tests were conducted to assess the aerodynamic performance of single-, two-and three-stage Savonius rotor systems with both semicircular and twisted blades.

337 citations

04 May 1982
TL;DR: In this paper, the Ffowcs Williams-Hawkings (FW-H) equation is used for the calculation of the noise produced by helicopter rotors, which can be used to control the noise of existing helicopters by avoiding noisy regimes of flight or by redesigning the main and tail rotors.
Abstract: An accurate prediction of the noise produced by helicopters requires a good understanding of the noise generating mechanisms involved Such an understanding can lead to controlling the noise of existing helicopters by avoiding noisy regimes of flight or by redesigning the main and tail rotors The present investigation is concerned with approaches which are suitable for the calculation of discrete frequency noise of helicopter rotors The governing differential equation of acoustics used in a consideration of acoustic formulations is the Ffowcs Williams-Hawkings (FW-H) equation Attention is given to a method reported by Farassat (1981), a method developed by Succi (1979), and a procedure discussed by Woan and Gregorek (1978)

326 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
2023143
2022295
2021216
2020232
2019275
2018278