Results 261 to 270 of about 68,215 (317)

Aerodynamic noise from motor vehicles

The Journal of the Acoustical Society of America, 1975
In motor vehicles there are two primary sources of aerodynamic sound: the engine-cooling fan and the interaction of either the entire vehicle or some of its components with the airstream created by vehicle movement. The mechanisms for sound generated by these sources are discussed in terms of the associated physical parameters (fan size, fan-blade ...
Robert C. Chanaud, Douglas Muster
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Aerodynamic Noise of Ground Vehicles

SAE Technical Paper Series, 1991
<div class="htmlview paragraph">As engine, tire, and other automobile noise is reduced and as driving speeds increase, aerodynamic noise sources on ground vehicles are becoming relatively more important. They often dominate at cruise speeds of 65 mph.
Albert R. George, John R. Callister
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Circular saw aerodynamic noise

Journal of Sound and Vibration, 1992
Summary: The aerodynamically induced noise of an idling circular saw turning at high speed is investigated both experimentally and analytically. The origin of the noise is shown to be fluctuating lift forces acting on the teeth. The sources at the teeth radiate incoherently as baffled dipoles and account for the generated noise.
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Wing flap aerodynamic noise suppression

The Journal of the Acoustical Society of America, 1992
An arrangement for suppressing aerodynamic noise generated by cavity effect interaction between a wing flap shroud and one or more partially deployed trailing edge flaps. Noise suppression vanes are so positioned with respect to the shroud lower trailing edge and the leading edge of the wing flaps at partial deployment that eddies and vortices ...
Ian R. Whitehouse, James K. Chu
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Aerodynamic Noise in Supersonic Wind Tunnels

Journal of the Aerospace Sciences, 1961
Hot-wire measurements in the free stream of a supersonic wind tunnel were made in the Mach number range of 1.6 to 5.0. I t is shown that the mass-flow fluctuations increase very rapidly with increasing Mach number. If the fluctuation field is assumed to consist of sound waves—an assumption tha t is consistent with the measurements—the sound intensity ...
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Aerodynamic Noise produced by a Gliding Owl

Nature, 1971
THE flight of owls has been reported by ornithologists to be unusually quiet1. This conclusion is generally based on the success of the owl's hunting technique and on the relative inability of the observer to distinguish the owl aurally from other birds.
H D, Gruschka, I U, Borchers, J G, Coble
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Aircraft Aerodynamic Noise Measurement

2007
Aircraft noise in flight is mostly produced from propulsion system (engine and propeller, for propeller driven aircraft), but one part of the noise come from air stream over aircraft surfaces (wings, airframe etc) – it is aerodynamic or airframe noise.
Domitrović, Anita, Bazijanac, Ernest, Franjković, Davor   +2 more
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Direct Computation of Aerodynamic Noise

1993
In his pioneering work Lighthill formulated the problem of predicting the noise radiated by an unsteady flow in terms of an acoustic analogy. However, in order to predict the far-field noise the acoustic source terms of such acoustic analogies must be known accurately.
Sanjiva K. Lele, Parviz Moin, Tim Colonius, Brian Mitchell   +3 more
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On Noise of Aerodynamic Origin

The Journal of the Acoustical Society of America, 1953
An attempt is made in this paper to classify noises of various aerodynamic origin by means of an efficiency of conversion from mechanical to acoustical energy, and also by means of representative spectra associated with corresponding characteristic frequencies.
Osman K. Mawardi, Ira Dyer
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Lighthill’s Theory of Aerodynamic Noise

2012
In 1952, Lighthill [61] gave the first formulation of aerodynamic sound, which is based on an analogy of sound radiated by fluctuating monopole, dipole, or quadrupole sound sources. Lighthill’s treatment of the subject will be discussed in this chapter, which starts with a derivation of an equation of sound.
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