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The near pressure field of co-axial subsonic jets

Published online by Cambridge University Press:  25 September 2008

C. E. TINNEY  and
P. JORDAN
C. E. TINNEY
Affiliation:
Laboratoire d'Etudes Aérodynamiques – UMR CNRS 6609, CNRS, Université de Poitiers, ENSMA, France
P. JORDAN
Affiliation:
Laboratoire d'Etudes Aérodynamiques – UMR CNRS 6609, CNRS, Université de Poitiers, ENSMA, France
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Abstract

Results are presented from pressure measurements performed in the irrotational near field of unbounded co-axial jets. Measurements were made for a variety of velocity and temperature ratios, and configurations both with and without serrations on the secondary nozzle lip. The principal objective of the study is to better understand the near pressure field of the jet, what it can tell us regarding the underlying turbulence structure, and in particular how it can be related to the source mechanisms of the flow.

A preliminary analysis of the axial, temporal and azimuthal structure of the pressure field shows it to be highly organized, with axial spatial modes (obtained by proper orthogonal decomposition) which resemble Fourier modes. The effects of serrations on the pressure fluctuations comprise a global reduction in level, a change in the axial energy distribution, and a modification of the evolution of the characteristic time scales.

A further analysis in frequency–wavenumber space is then performed, and a filtering operation is used to separate the convective and propagative footprints of the pressure field. This operation reveals two distinct signatures in the propagating component of the field: a low-frequency component which radiates at small angles to the flow axis and is characterized by extensive axial coherence, and a less-coherent high-frequency component which primarily radiates in sideline directions. The serrations are found to reduce the energy of the axially coherent propagating component, but its structure remains fundamentally unchanged; the high-frequency component is found to be enhanced. A further effect of the serrations involves a relative increase of the mean-square pressure level of the acoustic component – integrated over the measurement domain – with respect to the hydrodynamic component. The effect of increasing the velocity and temperature of the primary jet involves a relative increase in the acoustic component of the near field, while the hydrodynamic component remains relatively unchanged: this shows that the additional acoustic energy is generated by the mixing region which is produced by the interaction of the inner and the outer shear layers, whereas the hydrodynamic component of the near field is primarily driven by the outer shear layer.

Type
Papers
Information
Journal of Fluid Mechanics , Volume 611 , 25 September 2008 , pp. 175 - 204
Copyright
Copyright © Cambridge University Press 2008

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References

REFERENCES

Alkislar, M. B., Krothapalli, A. & Butler, G. W. 2007 The effect of streamwise vortices on the aeroacoustics of a Mach 0.9 jet. J. Fluid Mech. 578, 139–169.Google Scholar
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, 1–33.CrossRefGoogle Scholar
Aubry, N., Holmes, P., Lumley, J. & Stone, E. 1988 The dynamics of coherent structure in the wall region of a turbulent boundary layer. J. Fluid Mech. 192, 115–173.Google Scholar
Barré, S., Bogey, C., Fleury, V., Bailly, C. & Juvé, D. 2006 Experimental study of the properties of near field and far field jet noise. AIAA Paper 2006-2649.Google Scholar
Berkooz, G., Holmes, P. & Lumley, J. L. 1993 The Proper Orthogonal Decomposition in the analysis of turbulent flows. Annu. Rev. Fluid Mech. 25, 539–575.Google Scholar
Bogey, C., Bailly, C. & Juvé, D. 2003 Noise investigation of a high subsonic, moderate Reynolds number jet using compressible large eddy simulation. Theor. Comput. Fluid Dyn. 16, 273–297.CrossRefGoogle Scholar
Bradshaw, P., Ferriss, D. H. & Johnson, R. F. 1964 Turbulence in the noise-producing region of a circular jet. J. Fluid Mech. 19, 591–624.CrossRefGoogle Scholar
Brown, C. A. & Bridges, J. 2006 Acoustic efficiency of azimuthal modes in jet noise using chevron nozzles. AIAA Paper 2006-2654.Google Scholar
Citriniti, J. H. & George, W. K. 2000 Reconstruction of the global velocity field in the axisymmetric mixing layer utilizing the proper orthogonal decomposition. J. Fluid Mech. 418, 137–166.Google Scholar
Coiffet, F., Jordan, P., Delville, J., Gervais, Y. & Ricaud, F. 2006 Coherent structures in subsonic jets: a quasi-irrotational source mechanism? Intl J. Aeroacoust. 5, 67–89.CrossRefGoogle Scholar
Crighton, D. G. & Huerre, P. 1990 Shear layer pressure fluctuations and superdirective acoustic sources. J. Fluid Mech. 220, 355–368.Google Scholar
Delville, J., Ukeiley, L., Cordier, L., Bonnet, J. P. & Glauser, M. N. 1999 Examination of large scale structures in a turbulent plane mixing layer. Part 1. Proper Orthogonal Decomposition. J. Fluid Mech. 391, 91–122.Google Scholar
Ewing, D., Frohnapfel, B., George, W. K., Pedersen, J. M. & Westerweel, J. 2007 Two-point similarity in the round jet. J. Fluid Mech. 577 309–330.Google Scholar
Ffowcs Williams, J. E. & Kempton, A. J. 1978 The noise from the large-scale structure of a jet. J. Fluid Mech. 84, 673–694.Google Scholar
Freund, J. B. 2001 Noise sources in a low-Reynolds-number turbulent jet at Mach 0.9. J. Fluid Mech. 438, 277–305.CrossRefGoogle Scholar
George, W. K., Beuther, P. D. & Arndt, R. E. A. 1984 Pressure spectra in turbulent free shear flows. J. Fluid Mech. 148, 155–191.CrossRefGoogle Scholar
Glauser, M. N. & George, W. K. 1987 Orthogonal decomposition of the axisymmetric jet mixing layer including azimuthal dependence. Advances in Turbulence (ed. Comte-Bellot, G. & Mathieu, J.), pp. 357–366. Springer.CrossRefGoogle Scholar
Guerin, S. & Michel, U. 2006 Circumferential analysis of the near pressure field of a co-axial subsonic jet. Presented at 10th CEAS-ASC Workshop: Jet Noise Prediction Methodologies, Recent Developments. Dublin, Ireland.Google Scholar
Guitton, A., Jordan, P., Laurendeau, E. & Delville, J. 2007 Velocity dependence of the near pressure field of subsonic jets: understanding the associated source mechanisms. AIAA Paper 2007-3661.Google Scholar
Harper-Bourne, M. 2004 On modelling the hydrodynamic field of high-speed jets 10th AIAA/CEAS Aeroacoustics conference, Manchester, May 2004.Google Scholar
Howes, W. L. 1960 Distribution of time-averaged pressure fluctuations along the boundary of a round subsonic jet. NASA Tech. Note D-468.Google Scholar
Hussain, A. K. M. F. & Clark, A. R. 1981 On the coherent structure of the axisymmetric mixing layer: a flow-visualization study. J. Fluid Mech. 104, 263–294.Google Scholar
Jordan, P. & Gervais, Y. 2008 Subsonic jet aeroacoustics: associating experiment, modelling and simulation. Exps. Fluids 44, 1–21.Google Scholar
Jordan, P., Tinney, E., Delville, J., Coiffet, F., Glauser, M. N. & Hall, A. 2005 Low-dimensional signatures of the sound production mechanisms in subsonic jets: Towards their identification and control. AIAA Paper 2005-4647.Google Scholar
Juvé, D., Sunyach, M. & Comte-Bellot, G. 1980 Intermittency of the noise emission in subsonic cold jets. J. Sound Vib. 71, 319–332.Google Scholar
Keast, D. N. & Maidanik, G. Studies in the near field of noise properties of a small air jet. Bolt, Beranek and Newman, Report 1272, February 1966.Google Scholar
Kerhervé, F., Jordan, P., Gervais, Y., Valière, J. C. & Braud, P. 2004 Two-point laser doppler velocimetry measurements in a Mach 1.2 cold supersonic jet for statistical aeroacoustic source model. Exps. Fluids 37, 419–437.CrossRefGoogle Scholar
Ko, N. W. M. & Davies, P. O. A. L. 1971 The near field within the potential cone of subsonic cold jet. J. Fluid Mech. 50, 49–78.Google Scholar
Ko, N. W. M. & Kwan, S. H. 1976 The initial region of subsonic coaxial jets. J. Fluid Mech. 73, 305–332.CrossRefGoogle Scholar
Kopiev, V. F., Zaitsev, M. Yu., Chernyshev, S. A. & Kotova, A. N. 1999 The role of large-scale vortex in a turbulent jet noise. AIAA Paper 1999-1839.Google Scholar
Lau, J. C., Fisher, M. J. & Fuchs, H. V. 1972 The intrinsic structure of turbulent jets. J. Sound Vib. 22, 379–406.Google Scholar
Laufer, J. & Yen, T. 1983 Noise generation by a low Mach number jet. J. Fluid Mech. 134, 1–34.Google Scholar
Laurendeau, E., Jordan, P., Delville, J. & Bonnet, J.-P. 2008 Source mechanism identification by near field-far field pressure correlations in subsonic jets. Intl J. Aeroacous. 7, 41–68.Google Scholar
Lumley, J. L. 1967 The structure of inhomogenous turbulent flows. In Atmospheric Turbulence and Radio Wave Propagation (ed Yaglom, A. M. & Tatarski, V. I.), pp. 166–178. Moscow: Nauka.Google Scholar
Lumley, J. L. 1981 Coherent structure in turbulence. In Transition and Turbulence (ed. Meyer, R. E.), p. 215. Academic.Google Scholar
Mayes, W. H., Lanford, W. E. & Hubbard, H. H. 1959 Near-field and far-field noise surveys of solid-fuel rocket engines for a range of nozzle exit pressures. NASA Tech. Note D-21.Google Scholar
Mollo-Christensen, E. 1963 Measurements of near field pressure of subsonic jets. NATO AGARD Rep. 449.Google Scholar
Moser, R. D. 1994 Kolmogorov inertial range spectra for inhomogeneous turbulence. Phys. Fluids 6, 794–801.Google Scholar
Ollerhead, J. B. 1967 On the prediction of the near field noise of supersonic jets. NASA Rep. CR-857.Google Scholar
Picard, C. & Delville, J. 2000 Pressure velocity coupling in a subsonic round jet. Intl J. Heat Fluid Flow 21, 359–364.CrossRefGoogle Scholar
Reba, R., Narayanan, S., Colonius, T. & Suzuki, T. 2005 Modeling jet noise from organized structures using near-field hydrodynamic pressure. AIAA Paper 2005-3093.CrossRefGoogle Scholar
Ribner, H. S. 1964 The generation of sound by turbulent jets. Adv. Appl. Mech. 8.CrossRefGoogle Scholar
Ricaud, F. 2003 Étude de l'identification des sources acoustiques è partir du couplage de la pression en champ proche et de l'orgonization instantanée de la zone de mélange de jet. PhD Thesis, l'Université de Poitiers, Potiers, France.Google Scholar
Skeen, A. 2007 The development of high-speed PIV techniques and their application to jet noise measurements. PhD Dissertation, University of Warwick, UK.Google Scholar
Suzuki, T. & Colonius, T. 2006 Instability waves in a subsonic round jet detected using a near-field phased microphone array J. Fluid Mech. 565, 197–226.Google Scholar
Tam, C., Golebiowski, M. & Seiner, J. 1996 On the two components of turbulent mixing noise from supersonic jets. AIAA Paper 1996-1716.Google Scholar
Tester, B. J. & Fisher, M. J. 2006 A contribution to the understanding and prediction of jet noise generation by forced mixers: Part III applications. AIAA Paper 2006-2542.Google Scholar
Tinney, C. E., Jordan, P., Hall, A., Delville, J. & Glauser, M. N. 2007 A Time-resolved estimate of the turbulence and sound source mechanisms in a subsonic jet flow. J. Turbul. 8 (7), 1–20.Google Scholar
Viswanathan, K., Shur, M. L., Spalart, P. R. & Strelets, M. K. 2006 Computation of the flow and noise of round and beveled nozzles. AIAA Paper 2006-2445.CrossRefGoogle Scholar
Wills, J. A. B. 1964 On convection velocities in turbulent shear flows. J. Fluid Mech. 20, 417–432.CrossRefGoogle Scholar