Journal ArticleDOI
Sound Generation by Turbulence and Surfaces in Arbitrary Motion
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In this article, sound generation by turbulence and surfaces in arbitrary motion is discussed, and sound and multipole fields and governing equations are discussed. But sound generation is not discussed in this paper.Abstract:
Monograph on sound generation by turbulence and surfaces in arbitrary motion, discussing sound and multipole fields and governing equationsread more
Citations
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Journal ArticleDOI
Contributions to the theory of aerodynamic sound, with application to excess jet noise and the theory of the flute
TL;DR: In this article, a reformulation of the Lighthill (1952) theory of aerodynamic sound is described, and the form of the acoustic propagation operator is established for a non-uniform mean flow in the absence of vortical or entropy gradient source terms.
Journal ArticleDOI
Computational aeroacoustics: progress on nonlinear problems of sound generation
Tim Colonius,Sanjiva K. Lele +1 more
TL;DR: A hierarchy of computational approaches that range from semi-empirical schemes that estimate the noise sources using mean-flow and turbulence statistics, to high-fidelity unsteady flow simulations that resolve the sound generation process by direct application of the fundamental conservation principles is discussed in this paper.
Journal ArticleDOI
Analytical Comparison of the Acoustic Analogy and Kirchhoff Formulation for Moving Surfaces
TL;DR: In this article, the Lighthill acoustic analogy, as embodied in the Ffowcs Williams-Hawkings (FW-H) equation, is compared with the Kirchhoff formulation for moving surfaces.
Journal ArticleDOI
Basic principles of aerodynamic noise generation
TL;DR: In this paper, the authors give a simple, unified, analytical description of a wide range of mechanisms associated with the generation of sound by unsteady fluid motion, including radiation from compact and noncompact multipole sources, Lighthill's theory of sound emission from free turbulence, effects of source convection, sound generation from flow interaction with solid surfaces and inhomogeneities of the medium, and singular perturbation aspects of the aerodynamic sound problem.
Journal ArticleDOI
Modeling aerodynamically generated sound of helicopter rotors
TL;DR: In this article, the Kirchhoff formulation for moving surfaces is compared with the Ffowcs Williams Hawkings (FW-H) equation for the prediction of high-speed impulsive noise, in an effort to eliminate the need to compute the quadrupole contribution.
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.
Journal ArticleDOI
The Influence of Solid Boundaries upon Aerodynamic Sound
TL;DR: In this paper, an extension to Lighthill's general theory of aerodynamic sound was made to incorporate the influence of solid boundaries upon the sound field, and it was shown that these effects are exactly equivalent to a distribution of dipoles, each representing the force with which unit area of solid boundary acts upon the fluid.
Journal ArticleDOI
On Sound Generated Aerodynamically. II. Turbulence as a Source of Sound
TL;DR: The theory of sound generated aerodynamically is extended by taking into account the statistical properties of turbulent airflows, from which the sound radiated (without the help of solid boundaries) is called aerodynamic noise as mentioned in this paper.
Book ChapterDOI
Definition and simplest properties of generalized functions
I.M. Gel'fand,G.E. Shilov +1 more
TL;DR: A generalized function is defined as any linear continuous functional defined on K. The functionals [RK1] as discussed by the authors are defined as linear continuous functions on K and defined on a linear continuous function.