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A Wave model for Sound Generation in Circular Jets

Michalke, Alfons (1970) A Wave model for Sound Generation in Circular Jets. DLR-Forschungsbericht. Deutsche Forschungs- und Versuchsanstalt für Luft-und Raumfahrt, e.V..

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Abstract

A wave model is used for the investigation of sound generation in circular jets. The source term of the Lighthill equation is expressed by a Fourier series in the azimuthal angle, is Fourier-transformed with respect to time, and each component is assumed to be of wave-type in jet direction. A far-field solution for the sound pressure is derived in this way for single azimuth-frequency components. It is found that the sound field depends strongly on a convection parameter and on a jet thickness parameter. The influence of axisymmetric and azimuthal source components is discussed. For a special source term with arbitrarily chosen amplitude distribution the convection factor and the jet thickness factor of sound intensity are calculated and discussed. The influence of the amplitude distribution of the source components is found to be of minor importance.

Document Type:Monograph (DLR-Forschungsbericht)
Title:A Wave model for Sound Generation in Circular Jets
Authors:
AuthorsInstitution or Email of Authors
Michalke, AlfonsUNSPECIFIED
Date:November 1970
Number of Pages:31
Publisher:Deutsche Forschungs- und Versuchsanstalt für Luft-und Raumfahrt, e.V.
Series Name:Deutsche Luft- und Raumfahrt Forschungsbericht
Status:Published
Keywords:jet noise, sound generation, wave model, circular jet
Institution:Deutsche Forschungs-und Versuchsanstalt für Luft- und Raumfahrt
Department:Institut für Turbulenzforschung
HGF - Research field:Aeronautics, Space and Transport (old)
HGF - Program:Aeronautics
HGF - Program Themes:other
DLR - Research area:Aeronautics
DLR - Program:L - no assignement
DLR - Research theme (Project):L -- no assignement
Location: Berlin-Adlershof
Institutes and Institutions:Institute of Propulsion Technology > Engine Acoustic
Deposited By: Prof. Dr.-Ing. Ulf Michel
Deposited On:08 Feb 2010 08:55
Last Modified:08 Feb 2010 08:55

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