Modal analysis of jet near-field pressure fluctuation
International Journal of Numerical Methods for Heat & Fluid Flow
ISSN: 0961-5539
Article publication date: 5 September 2016
Abstract
Purpose
Unstable Kelvin-Helmholtz waves are suspected to be responsible for a large part of low-frequency 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.
Keywords
Acknowledgements
The ORINOCO project was granted by the European Union, as part of the 7th Framework Programme for Research and Technological Development, and by the Russian Government.
Citation
Brazier, J.-P., Huet, M., Léon, O. and Itasse, M. (2016), "Modal analysis of jet near-field pressure fluctuation", International Journal of Numerical Methods for Heat & Fluid Flow, Vol. 26 No. 7, pp. 2000-2012. https://doi.org/10.1108/HFF-07-2015-0289
Publisher
:Emerald Group Publishing Limited
Copyright © 2016, Emerald Group Publishing Limited