Skip to main content

On the hydrodynamic and acoustic nature of pressure proper orthogonal decomposition modes in the near field of a compressible jet

  • Matteo Mancinelli (a1), Tiziano Pagliaroli (a2), Roberto Camussi (a1) and Thomas Castelain (a3)

In this work an experimental investigation of the near-field pressure of a compressible jet is presented. The proper orthogonal decomposition (POD) of the pressure fluctuations measured by a linear array of microphones is performed in order to provide the streamwise evolution of the jet structure. The wavenumber–frequency spectrum of the space–time pressure fields re-constructed using each POD mode is computed in order to provide the physical interpretation of the mode in terms of hydrodynamic/acoustic nature. Specifically, non-radiating hydrodynamic, radiating acoustic and ‘hybrid’ hydro-acoustic modes are found based on the phase velocity associated with the spectral energy bumps in the wavenumber–frequency domain. Furthermore, the propagation direction in the far field of the radiating POD modes is detected through the cross-correlation with the measured far-field noise. Modes associated with noise emissions from large/fine scale turbulent structures radiating in the downstream/sideline direction in the far field are thus identified.

Corresponding author
Email address for correspondence:
Hide All
Arndt, R. E. A., Long, D. F. & Glauser, M. N. 1997 The proper orthogonal decomposition of pressure fluctuations surrounding a turbulent jet. J. Fluid Mech. 340, 133.
Berkooz, G., Holmes, P. & Lumley, J. L. 1993 The proper orthogonal decomposition in the analysis of turbulent flows. Annu. Rev. Fluid Mech. 25 (1), 539575.
Bonnet, J. P., Cole, D. R., Delville, J., Glauser, M. N. & Ukeiley, L. S. 1994 Stochastic estimation and proper orthogonal decomposition: complementary techniques for identifying structure. Exp. Fluids 17 (5), 307314.
Cavalieri, A. V. G., Jordan, P., Agarwal, A. & Gervais, Y. 2011 Jittering wave-packet models for subsonic jet noise. J. Sound Vib. 330 (18), 44744492.
Freund, J. B. & Colonius, T. 2009 Turbulence and sound-field POD analysis of a turbulent jet. Intl J. Aeroacoust. 8 (4), 337354.
Grizzi, S. & Camussi, R. 2012 Wavelet analysis of near-field pressure fluctuations generated by a subsonic jet. J. Fluid Mech. 698, 93124.
Howes, W. L.1960 Distribution of time-averaged pressure fluctuations along the boundary of a round subsonic jet. Technical Report NASA-TN-D-468. NASA.
Jordan, P. & Colonius, T. 2013 Wave packets and turbulent jet noise. Annu. Rev. Fluid Mech. 45, 173195.
Lighthill, M. J. 1952 On sound generated aerodynamically I. General theory. Proc. R. Soc. Lond. A 211 (1107), 564587.
Lilley, G. M. 1991 Jet noise classical theory and experiments. Aeroacoust. Flight Vehicles 1, 211289.
Mancinelli, M., Di Marco, A. & Camussi, R. 2017a Multi-variate and conditioned statistics of velocity and wall pressure fluctuations induced by a jet interacting with a flat-plate. J. Fluid Mech. 823, 134165.
Mancinelli, M., Pagliaroli, T., Di Marco, A., Camussi, R. & Castelain, T. 2017b Wavelet decomposition of hydrodynamic and acoustic pressures in the near field of the jet. J. Fluid Mech. 813, 716749.
Mancinelli, M., Pagliaroli, T., Di Marco, A., Camussi, R., Castelain, T. & Léon, O.2016 Hydrodynamic and acoustic wavelet-based separation of the near-field pressure of a compressible jet. In 22nd AIAA/CEAS Aeroacoustics Conference, AIAA Paper 2016-2864. American Institute of Aeronautics and Astronautics.
Picard, C. & Delville, J. 2000 Pressure velocity coupling in a subsonic round jet. Intl J. Heat Fluid Flow 21 (3), 359364.
Sasaki, K., Cavalieri, A. V. G., Silvestre, F. J., Jordan, P., Tissot, G. & Biau, D.2017 A framework for closed-loop flow control using the parabolized stability equations. In 23rd AIAA/CEAS Aeroacoustics Conference, AIAA Paper 2017-3003. American Institute of Aeronautics and Astronautics.
Suzuki, T. & Colonius, T. 2006 Instability waves in a subsonic round jet detected using a near-field phased microphone array. J. Fluid Mech. 565, 197226.
Tam, C. K. W., Golebiowski, M. & Seiner, J. M.1996 On the two components of turbulent mixing noise from supersonic jets. In 2nd AIAA/CEAS Aeroacoustics Conference, AIAA Paper 1996-1716. American Institute of Aeronautics and Astronautics.
Tinney, C. E. & Jordan, P. 2008 The near pressure field of co-axial subsonic jets. J. Fluid Mech. 611, 175204.
Tropea, C., Yarin, A. L. & Foss, J. F.(Eds) 2007 Springer Handbook of Experimental Fluid Mechanics, vol. 23. Springer Science & Business Media.
Recommend this journal

Email your librarian or administrator to recommend adding this journal to your organisation's collection.

Journal of Fluid Mechanics
  • ISSN: 0022-1120
  • EISSN: 1469-7645
  • URL: /core/journals/journal-of-fluid-mechanics
Please enter your name
Please enter a valid email address
Who would you like to send this to? *

JFM classification


Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed