Kinematic wavepacket model for broadband shock associated noise in underexpanded supersonic jets

Marcus H. Wong, Damon Honnery, Daniel Edgington-Mitchell, Alessandro Savarese, Peter Jordan

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

1 Citation (Scopus)

Abstract

Motivated by the success of wavepackets in modelling the noise from subsonic and perfectly-expanded supersonic jets, we apply the wavepacket model to imperfectly expanded supersonic jets. Previous work by Savarese et al. [1] adopted a kinematic single-point wavepacket model first formulated by Lele [2]. Recent studies with subsonic jets, however, have demonstrated the importance of capturing the ‘jittering’ of wavepackets in order to correctly predict the intensity of far-field sound. Following the analysis of Cavalieri and Agarwal [3], we extend their methodology to model the acoustic sources of broadband shock-associated noise in imperfectlyexpanded supersonic jets using cross-spectral densities of the turbulent and shock-cell velocity quantities. We model the downstream propagating vortices as wavepackets, with the aim of determining the relationship between coherence decay, the statistical representation of jitter, and broadband shock-associated noise. Unlike the subsonic case where inclusion of coherence decay amplifies sound pressure level over the whole acoustic spectrum, we find that it does not play a critical role in increasing sound amplitude for shock-cell noise. When higher-order shock-cell modes are used to capture high frequency noise, however, the inclusion of a jittering wavepacket is necessary.

Original languageEnglish
Title of host publication2018 AIAA/CEAS Aeroacoustics Conference
PublisherAmerican Institute of Aeronautics and Astronautics
ISBN (Print)9781624105609
DOIs
Publication statusPublished - 1 Jan 2018
EventAIAA/CEAS Aeroacoustics Conference 2018 - Atlanta, United States of America
Duration: 25 Jun 201829 Jun 2018
Conference number: 24th
https://arc.aiaa.org/doi/book/10.2514/MAA18

Conference

ConferenceAIAA/CEAS Aeroacoustics Conference 2018
CountryUnited States of America
CityAtlanta
Period25/06/1829/06/18
Internet address

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