Results 211 to 220 of about 5,970 (262)

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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On the Aerodynamic Noise of a Turbulent Jet

Journal of the Aerospace Sciences, 1961
Summary A new model is advanced for analyzing the broad-spectrum noise of a turbulent jet. The shear layer bounding the turbulent jet is assumed to play an important role in modifying the "quadrupole sound radiation" from the interior. To the sound-emit­ ting, small-scale turbulent eddies (with frequencies much higher than those of large-scale eddies),
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Automobile Aerodynamic Noise

SAE Technical Paper Series, 1990
<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 above 60 mph. Aspiration and leak noise are strong sources but generally can be controlled by known methods.
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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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The Source of Aerodynamic Noise

International Journal of Aeroacoustics, 2003
This paper is a tribute to Alan Powell's achievements and his extensive publications in hydro and aeroacoustics. 1 The theory of Aerodynamic Noise was established by Sir James Lighthill in 1952.
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COMPUTING AERODYNAMICALLY GENERATED NOISE

Annual Review of Fluid Mechanics, 1997
▪ Abstract  In contrast to computational aerodynamics, which has advanced to a fairly mature state, computational aeroacoustics (CAA) has only recently emerged as a separate area of study. Following a discussion of the classical field of aeroacoustics as introduced by Lighthill, the paper provides an overview and analysis of the problems associated ...
Valana L. Wells, Rosemary A. Renaut
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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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Generalized aerodynamic noise equation

The Physics of Fluids, 1975
An exact aerodynamic noise equation is formulated for Newtonian fluids. The cause−effect problem is discussed. Finally, the importance of external additions of mass, momentum, and energy is examined.
Chandraker, AL, Munjal, ML
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AERODYNAMIC NOISE: A CRITICAL SURVEY

Journal of Sound and Vibration, 2000
Annoyance due to railway noise is a particularly sensitive aspect of new high-speed projects. Many studies have shown that aerodynamic noise becomes significant above 300 km/h and can become predominant with the reduction of the contribution of rolling noise.
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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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