Results 51 to 60 of about 191,773 (209)
Nanjing Hangkong Hangtian Daxue XuebaoDynamic stall significantly limits the flight performance of helicopters. To reveal the mechanism behind the variations in aerodynamic moments and damping characteristics under unsteady freestream， a numerical simulation method for the unsteady flow ...
GAO Yuan +4 more
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Helicopter noise regulations: An industry perspective [PDF]
A review of helicopter noise measurement programs and noise reduction/economic studies of FAA is given along with a critique of a study which addresses the economic impact of noise reduction on helicopter noise.
Wagner, R. A.
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Vision-Based Fuzzy 2D Motion Control of a Model Helicopter [PDF]
, 2006 ©2006 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or distribution to servers or lists, or to reuse any ...
Demirli, K. +2 more
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Dynamic Stall Mechanisms of Pitching Airfoil: IDDES Study Across Different Mach Numbers
Applied SciencesThis study investigates dynamic stall mechanisms of a pitching NACA 0012 airfoil through high-fidelity computational fluid dynamics (CFD) simulations.
Simeng Jing +4 more
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The effect of vortex trap on helicopter blade lift [PDF]
, 2011 The 5-seater Aerospatiale AS350B helicopter has been chosen in this analysis in order to investigate the capabilities of the vortex trap in increasing the helicopter blade lift.
Yaakub, Mohd Fauzi
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Numerical modelling of the aerodynamic interference between helicopter and ground obstacles [PDF]
, 2017 Helicopters are frequently operating in confined areas where the complex flow fields that develop in windy conditions may result in dangerous situations.
Barakos, George N. +3 more
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Recent Langley helicopter acoustics contributions [PDF]
The helicopter acoustics program at NASA Langley has included technology for elements of noise control ranging from sources of noise to receivers of noise. The scope of Langley contributions for about the last decade is discussed.
Morgan, Homer G. +2 more
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Helicopter transmission testing at NASA Lewis Research Center [PDF]
The helicopter has evolved into a highly valuable air mobile vehicle for both military and civilian needs. The helicopter transmission requires advanced studies to develop a technology base for future rotorcraft advances.
Coy, John J., Lewicki, David G.
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Geometrically Nonlinear Analysis of Composite Beams Based Using a Space–Time Finite Element Method
AerospaceIn this paper, we present a transient-format time-continuous Galerkin finite element method for fully intrinsic geometrically exact beam equations that are energy-consistent.
Xin Hu, Lidao Chen, Yong Liu
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Results of the noise measurement program on a standard and modified OH-6A helicopter [PDF]
A field noise measurement program has been conducted on a standard OH-6A helicopter and one that had been modified by reducing the rotor speed, altering rotor tip shape, and treating the engine exhaust and inlet to reduce the external noise levels.
Henderson, H. R. +2 more
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