Modal analysis of jet near-field pressure fluctuation
Résumé
Purpose – Unstable Kelvin-Helmholtz waves are suspected to be responsible for a large part of lowfrequency noise radiation in high-speed jets. The purpose of this paper is to check the coherence of numerical and experimental data concerning this phenomenon, in the particular case of a cold subsonic jet.
Design/methodology/approach – In the present work, a cross-investigation of the near pressure
field is performed on three different data sets: large-eddy simulation (LES) computations, parabolised stability equations (PSE) semi-modal computations and microphone measurements, in order to determine the local amplitudes of unstable waves.
Findings – The large coherent structures are found in both LES and experimental results and they are also in good agreement with direct semi-modal computations carried out with the PSE approach.
Originality/value – This work confirms that the unstable wave packets can be extracted from both
LES and experimental results, provided that an appropriate modal decomposition is performed.
Origine : Fichiers produits par l'(les) auteur(s)
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