Acoustic analogy and alternative theories for jet noise prediction

Philip J. Morris, F. Farassat

Research output: Contribution to journalArticle

158 Citations (Scopus)

Abstract

Several methods for the prediction of jet noise are described. All but one of the noise prediction schemes are based on Lighthill's or Lilley's acoustic analogy, whereas the other is the jet noise generation model recently proposed by Tam and Auriault. In all of the approaches, some assumptions must be made concerning the statistical properties of the turbulent sources. In each case the characteristic scales of the turbulence are obtained from a solution of the Reynolds-averaged Navier-Stokes equation using a k-ε turbulence model. It is shown that, for the same level of empiricism, Tam and Auriault's model yields better agreement with experimental noise measurements than the acoustic analogy. It is then shown that this result is not because of some fundamental flaw in the acoustic analogy approach, but instead is associated with the assumptions made in the approximation of the turbulent source statistics. If consistent assumptions are made, both the acoustic analogy and Tam and Auriault's model yield identical noise predictions. In conclusion, a proposal is presented for an acoustic analogy that provides a clearer identification of the equivalent source mechanisms, as is a discussion of noise prediction issues that remain to be resolved.

Original languageEnglish (US)
Pages (from-to)671-680
Number of pages10
JournalAIAA journal
Volume40
Issue number4
DOIs
StatePublished - Apr 2002

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Acoustic noise
Acoustics
Turbulence models
Navier Stokes equations
Turbulence
Statistics
Defects

All Science Journal Classification (ASJC) codes

  • Aerospace Engineering

Cite this

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Acoustic analogy and alternative theories for jet noise prediction. / Morris, Philip J.; Farassat, F.

In: AIAA journal, Vol. 40, No. 4, 04.2002, p. 671-680.

Research output: Contribution to journalArticle

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