Single-point nonlinearity indicators for the propagation of high-amplitude jet noise

Lauren E. Falco, Anthony A. Atchley

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

Prediction schemes based on linear acoustics are often insufficient to describe the character of the noise radiated from a jet engine. Nonlinear evolution of jet noise is usually identified using linear extrapolation and spectral comparisons. Because it requires measurements at multiple locations, this method is susceptible to errors in the presence of ground reflections or meteorological effects, when the location of the source is uncertain, and in the near-field of the jet. Thus, an indicator of nonlinearity that can be derived from a measurement at a single point is desirable. This work introduces one such indicator based on a quantity found in a spectral Burgers equation derived by Morfey and Howell [AIAA J. 19, 986-992 (1981)]. The quantity, denoted Q p2p and commonly referred to as the QSD, is related to the nonlinear evolution of the signal. The indicator discussed here is a normalization of the QSD that assesses the relative importance of nonlinear, absorption, and spreading effects. For this reason, it is referred to as the spectral Gol'dberg number and is denoted Γs. It is applied to model-scale jet signatures and is shown to have larger values for higher jet Mach numbers and peak radiation angles relative to the jet axis.

Original languageEnglish (US)
Title of host publicationNonlinear Acoustics - Fundamentals and Applications - ISNA18 - 18th International Symposium on Nonlinear Acoustics
Pages381-384
Number of pages4
Volume1022
DOIs
StatePublished - Aug 15 2008
Event18th International Symposium on Nonlinear Acoustics, ISNA18 - Stockholm, Sweden
Duration: Jul 7 2008Jul 10 2008

Other

Other18th International Symposium on Nonlinear Acoustics, ISNA18
CountrySweden
CityStockholm
Period7/7/087/10/08

Fingerprint

jet aircraft noise
nonlinearity
propagation
jet engines
Burger equation
scale models
Mach number
extrapolation
near fields
signatures
acoustics
radiation
predictions

All Science Journal Classification (ASJC) codes

  • Physics and Astronomy(all)

Cite this

Falco, L. E., & Atchley, A. A. (2008). Single-point nonlinearity indicators for the propagation of high-amplitude jet noise. In Nonlinear Acoustics - Fundamentals and Applications - ISNA18 - 18th International Symposium on Nonlinear Acoustics (Vol. 1022, pp. 381-384) https://doi.org/10.1063/1.2956236
Falco, Lauren E. ; Atchley, Anthony A. / Single-point nonlinearity indicators for the propagation of high-amplitude jet noise. Nonlinear Acoustics - Fundamentals and Applications - ISNA18 - 18th International Symposium on Nonlinear Acoustics. Vol. 1022 2008. pp. 381-384
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Falco, LE & Atchley, AA 2008, Single-point nonlinearity indicators for the propagation of high-amplitude jet noise. in Nonlinear Acoustics - Fundamentals and Applications - ISNA18 - 18th International Symposium on Nonlinear Acoustics. vol. 1022, pp. 381-384, 18th International Symposium on Nonlinear Acoustics, ISNA18, Stockholm, Sweden, 7/7/08. https://doi.org/10.1063/1.2956236

Single-point nonlinearity indicators for the propagation of high-amplitude jet noise. / Falco, Lauren E.; Atchley, Anthony A.

Nonlinear Acoustics - Fundamentals and Applications - ISNA18 - 18th International Symposium on Nonlinear Acoustics. Vol. 1022 2008. p. 381-384.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

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Falco LE, Atchley AA. Single-point nonlinearity indicators for the propagation of high-amplitude jet noise. In Nonlinear Acoustics - Fundamentals and Applications - ISNA18 - 18th International Symposium on Nonlinear Acoustics. Vol. 1022. 2008. p. 381-384 https://doi.org/10.1063/1.2956236