Results 31 to 40 of about 2,024 (79)
Available information on the physical characteristics of the noise generated by wind turbines is summarized, with example sound pressure time histories, narrow- and broadband frequency spectra, and noise radiation patterns. Reviewed are noise measurement
Hubbard, Harvey H., Shepherd, Kevin P.
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NASA research activities in aeropropulsion [PDF]
NASA is responsible for advancing technologies related to air transportation. A sampling of the work at NASA's Lewis Research Center aimed at improved aircraft propulsion systems is described.
Mccarthy, J. F., Jr., Weber, R. J.
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Prediction and reduction of rotor broadband noise [PDF]
Prediction techniques which can be or have been applied to subsonic rotors, and methods for designing helicopter rotors for reduced broadband noise generation are summarized.
Aravamudan, K. S., Hayden, R. E.
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Water waves generated by the translatory and oscillatory surface disturbance [PDF]
, 1957 The problem under consideration is that of two-dimensional gravity waves in water generated by a surface disturbance which oscillates with frequency Ω/2π and moves with constant rectilinear velocity U over the free water surface.
Wu, T. Yao-tsu
core
Spatial Correlation in the Ambient Core Noise Field of a Turbofan Engine [PDF]
An acoustic transfer function relating combustion noise and turbine exit noise in the presence of enclosed ambient core noise is investigated using a dynamic system model and an acoustic system model for the particular turbofan engine studied and for a ...
Miles, Jeffrey Hilton
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86th Annual Meeting of the Meteoritical Society (2024)
Meteoritics &Planetary Science, Volume 59, Issue S1, Page A1-A468, August 2024.
wiley +1 more source
The outlook for aeronautics, 1980 - 2000 - Study report [PDF]
Trends in civil and military aviation in the period 1980-2000 are examined in terms of the role that NASA should play in aeronautical research and development during this period.
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A semi-analytic approach to the self induced motion of vortex sheets [PDF]
The rolling up of the trailing vortex sheet produced by a wing of finite span was calculated as a series expansion in time. For a vorticity distribution corresponding to a wing with cusped tips, the shape of the sheet was found by summing the series ...
Schwartz, L. W.
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Publications of the Jet Propulsion Laboratory 1989 [PDF]
This bibliography describes and indexes by primary author the externally distributed technical reporting, released during 1989, that resulted from scientific and engineering work performed, or managed, by JPL.
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A study of the variable impedance surface concept as a means for reducing noise from jet interaction with deployed lift-augmenting flaps [PDF]
The feasibility of quieting the externally-blown-flap (EBF) noise sources which are due to interaction of jet exhaust flow with deployed flaps was demonstrated on a 1/15-scale 3-flap EBF model.
Chanaud, R. C. +2 more
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