Results 271 to 280 of about 232,137 (308)

A study of helicopter main rotor noise in hover

10th Aeroacoustics Conference, 1986
Some fundamental aspects of rotor noise generation and radiation are presented. Data on which the study is based were obtained during a hover test at the NASA Ames Outdoor Aerodynamic Research Facility of a one-sixth-scale, four-bladed, helicopter rotor. The test site provided an open environment ideal for acquiring good acoustic data.
C. KITAPLIOGLU, C. KINNEY
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The Main Rotor

2022
Kay Bruce, Occhiato John
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Failure of a Helicopter Main Rotor Blade

1992
Abstract A Marine Corps helicopter crash was investigated. Efforts were directed to the failure of one of the main rotor blades that had apparently separated in the air. The apparent failure of a blade integrity monitor (BIM) system was also considered.
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VIBRATIONS OF A HELICOPTER ROTOR SYSTEM AND FUSELAGE INDUCED BY THE MAIN ROTOR BLADES IN FLIGHT

1953
Abstract : Based on a simplified model of the hub-fuselage structure, a theoretical analysis is made of the response of the hub and fuselage of a helicopter in flight to harmonic forces transmitted by the rotor blades to the hub both in, and normal to, the plan of rotation.
H. REISSNER, SHAO W. YUAN, MORRIS MORDUCHOW   +2 more
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The Bearingless Main Rotor

Journal of the American Helicopter Society, 1980
Peter G. C. Dixon, Harold E. Bishop
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Effect of rotor blade tip shape on helicopter main-rotor performance

2021
EFFECT OF ROTOR BLADE TIP SHAPE ON HELICOTER MAIN-ROTOR PERFORMANCE SUMMARY A helicopter is an aircraft that uses rotating wings to provide lift, propulsion, and control. The rotary wings can produce aerodynamics forces, which are generated by the relative motion of a wing surface with respect to the air, even when the velocity of the vehicle itself is
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Scaling of helicopter main rotor noise in hover

24th Aerospace Sciences Meeting, 1986
A 2.1-m-diam, one-sixth-scale model helicopter main rotor was tested in hover at the NASA Ames Outdoor Aerodynamic Research Facility. It had previously been tested in hover in the NASA Ames 40- by 80-Foot Wind Tunnel test section. The primary objective of the tests was to obtain acoustic and performance data on a medium-scale rotor at various thrust ...
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Design Study of Expendable Main Rotor Blades

1972
Abstract : A design study is performed to determine the feasibility and cost advantages of expendable main rotor blades designed for the UH-1H helicopter. Technical feasibility, manufacturing cost, reliability, maintainability, and life-cycle costs were determined.
Carroll R. Akeley, Paul F. Maloney, Michael C. Frengley   +2 more
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Tail Rotor Performance in Presence of Main Rotor, Ground, and Winds

Journal of the American Helicopter Society, 1974
Wayne Wiesner, Gary Kohler
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Uncertainty Quantification of the Main Rotor Blades Measurements

2017
This chapter provides a novel approach in the field of uncertainty assessment of the experimental investigation of mechanical properties of load carrying structures made of composite material. A combination of experimental methods are used hereto. In the experimental part, different test configurations were taken into account.
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