Journal ArticleDOI
Sound radiation from inflow turbulence in axial flow fans
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TLDR
In this paper, the sound radiated when inflow turbulence is present in axial flow fans has been investigated, and two noise radiating mechanisms can be identified: (i) interaction of turbulence with the rotor potential field results in a quadrupole-type volume source distribution, producing flow-interaction noise; (ii) impingement of turbulence on the blades results in dipole type (fluctuating force) surface source distribution.About:
This article is published in Journal of Sound and Vibration.The article was published on 1971-11-22. It has received 15 citations till now. The article focuses on the topics: Sound power & Turbulence.read more
Citations
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Journal ArticleDOI
Helicopter noise: state-of-the-art
TL;DR: In this paper, the main and tail rotors of a helicopter are evaluated and the bases for annoyance and audibility of helicopter external noise are discussed, with particular emphasis on the noise due to the helicopter main rotor.
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Rotating blades and aerodynamic sound
TL;DR: The history of research on rotating blade noise is reviewed in this paper, from early studies of propeller radiation to current work on aircraft-engine fans, with emphasis on fundamental aspects of aerodynamic sound generation by blades.
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Pressure pulsations in piping system excited by a centrifugal turbomachinery taking the damping characteristics into consideration
I. Hayashi,Shigehiko Kaneko +1 more
TL;DR: In this article, a one-dimensional excitation source model for a compressor or a pump is introduced based on the equation of motion, so as to incorporate the non-linear damping proportional to velocity squared in the total piping system including the compressor or pump.
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A review of rotating blade noise technology
TL;DR: In this article, the authors provide a general technical background for the problems of noise due to rotating blades and present a bibliography of some of the more recent work in the areas of rotor and propeller noise, compressor and fan noise, and duct acoustics.
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An experimental investigation of the sources of propeller noise due to the ingestion of turbulence at low speeds
D. F. Scharpf,Thomas J. Mueller +1 more
TL;DR: In this paper, a four bladed, 10 in. diameter propeller operating in air at a rotational speed of 3000 RPM and a freestream velocity of 33 ft/s was experimentally analyzed using hotwire and microphone measurements in an anechoic wind tunnel.
References
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Journal ArticleDOI
On Sound Generated Aerodynamically. I. General Theory
TL;DR: In this paper, a theory for estimating the sound radiated from a fluid flow, with rigid boundaries, which as a result of instability contains regular fluctuations or turbulence is initiated, based on the equations of motion of a gas.
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The Measurement of Power Spectra
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Some Aspects of Non-Stationary Airfoil Theory and Its Practical Application
TL;DR: In this paper, the lift and moment of a rigid airfoil passing through a vertical-gust pattern having a sinusoidal distribution of intensity were derived for two-dimensional thin airfoils in non-uniform motion.
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Theory relating to the noise of rotating machinery
TL;DR: In this paper, the authors extended the theory of sound generation by multibladed single-stage fans operating in a free field and showed that the quadrupole effects are important for low-speed, few-bladed fans in the first harmonics.