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Experimental investigation of turbulent density fluctuations and noise generation from heated jets

Published online by Cambridge University Press:  30 October 2007

J. PANDA
J. PANDA*
Affiliation:
Ohio Aerospace Institute and NASA Glenn Research Center, Brookpark, OH 44135, USA
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Abstract

Low-frequency noise sources in heated single-stream jets were identified by cross-correlating turbulent density fluctuations ρ′ with the far-field sound pressure fluctuations p′. The turbulent density fluctuations were measured by a molecular Rayleigh-scattering technique. For a fixed jet velocity Uj, the normalized correlation coefficient 〈ρ′; p′〉/(ρ′rmsp′rms is found to increase progressively with an increase in the plume temperature (subscript rms stands for root-mean-square). The result indicates an improvement of the noise radiation efficiency with heating. Directly measured noise spectra from fixed velocity jets with increasing temperature ratio show confusing trends. However, if such spectra are normalized by theplume density, then a consistent trend of increasing noise level with increased plume temperature emerges. The increased noise is the most prominent at the low-frequency end, consistent with the correlation data. The effect of increasing jet velocity keeping the plume temperature constant was also studied. The correlation coefficients were found to improve significantly with velocity; a result consistent with prior observation from unheated jets. Additional findings on the time-averaged density variations and the changes in the air density fluctuations with increasing plume temperature are also discussed.

Type
Papers
Information
Journal of Fluid Mechanics , Volume 591 , 25 November 2007 , pp. 73 - 96
Copyright
Copyright © Cambridge University Press 2007

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References

REFERENCES

Bogey, C. & Bailly, C. 2005 Investigation of sound sources in subsonic jets using causality methods on LES data. AIAA Paper 2005-2885.CrossRefGoogle Scholar
Bridges, J. & Brown, C. A. 2005 Validation of the small hot jet acoustic rig for aeroacoustics research. AIAA Paper 2005-2846.CrossRefGoogle Scholar
Bridges, J. & Wernet, M. P. 2003 Measurements of the aero-acoustic sound source in hot jets. AIAA Paper 2003-3130.CrossRefGoogle Scholar
Doty, M. J. & McLaughlin, D. K. 2003 Acoustic and mean flow measurements of high-speed, helium air mixture jets. Intl J. Aeroacoust. 2, 293–333.CrossRefGoogle Scholar
Fisher, M. J., Lush, P. A. & Harper-Bourne, M. 1973 Jet noise. J. Sound Vib. 28, 563–585.CrossRefGoogle Scholar
Freund, J. B. 2002 Turbulent jet noise: shear noise, self noise and other contributions. AIAA Paper 2002-2423.Google Scholar
Goldstein, M. E. 1976 Aeroacoustics. McGraw-Hill.Google Scholar
Hoch, R. G., Duponchel, J. P., Cocking, B. J. & Bryce, W. D. 1973 Studies of the influence of density on jet noise. J. Sound Vib. 28, 649–668.CrossRefGoogle Scholar
Hugo, R. J. & McMackin, L. 1997 Non-intrusive linearized stability experiments on a heated axisymmetric jet. AIAA Paper 1997-1965.CrossRefGoogle Scholar
Lau, J. C. 1981 Effects of exit Mach number and temperature on mean-flow and turbulence characteristics in round jets. J. Fluid Mech. 105, 193–218.CrossRefGoogle Scholar
Lepicovsky, J., Ahuja, K. K., Brown, W. H., Salikuddin, M. & Morris, P. J. 1988 Acoustically excited heated jets, Part III: Mean flow data. NASA CR 4129.Google Scholar
Lilley, G. M. 1991 Jet noise classical theory and experiments. Aeroacoustics of Flight Vehicles: Theory and Practice, Vol. I. Noise Sources (ed. Hubbard, H. H.). NASA RP 1258.Google Scholar
Michalke, A. & Michel, U. 1979 Prediction of jet noise in flight from static tests. J. Sound Vib. 67, 341–367.CrossRefGoogle Scholar
Monkewitz, P. A., Bechert, D. W., Barsikow, B. & Lehmann, B. 1990 Self excited oscillations and mixing in a heated round jet. J. Fluid Mech. 213, 611–639.CrossRefGoogle Scholar
Morel, T. 1975 Comprehensive design of axisymmetric wind tunnel contractions. ASME Paper 75 FE-17.Google Scholar
Morfey, C. L. 1973 Amplification of aerodynamic noise by convected flow inhomogeneities. J. Sound Vib. 31, 391–397.CrossRefGoogle Scholar
Morfey, C. L., Szewczyk, V. M. & Tester, B. J. 1978 New scaling laws for hot and cold jet mixing noise based on a geometric acoustics model. J. Sound Vib. 61, 255–292.CrossRefGoogle Scholar
Ötügen, M. V. & Namer, I. 1988 Rayleigh scattering temperature measurements in a plane turbulent air jet at moderate Reynolds numbers. Exps. Fluids 6, 461–466.CrossRefGoogle Scholar
Panda, J. & Seasholtz, R. G. 2002 Experimental investigation of density fluctuations in high speed jets and correlation with generated noise. J. Fluid Mech. 450, 97–130.CrossRefGoogle Scholar
Panda, J., Seasholtz, R. G., Mielke, A. F., Elam, K. A. & Eck, D. G. 2004 Effect of heating on turbulent density fluctuations and noise generation from high speed jets. AIAA Paper 2004-3016.CrossRefGoogle Scholar
Panda, J., Seasholtz, R. G. & Elam, K. A. 2005 Investigation of noise sources in high-speed jets via correlation measurements. J. Fluid Mech. 537, 349–385.CrossRefGoogle Scholar
Russ, S. & Strykowski, P. J. 1993 Turbulent structure and entrainment in heated jets: the effect of initial conditions. Phys. Fluids A: Fluid Dyn. 5, 3216–3225.CrossRefGoogle Scholar
Tam, C. K. W. & Auriult, L. 1999 Jet mixing noise from fine scale turbulence. AIAA J. 37, 145–153.CrossRefGoogle Scholar
Tam, C. K. W., Golebiowski, M. & Seiner, J. M. 1996 On the two components of turbulent mixing noise from supersonic jets. AIAA Paper 96-1716.CrossRefGoogle Scholar
Tanna, H. K. 1977 An experimental study of jet noise, Part I: Turbulent mixing noise. J. Sound Vib. 50, 405–428.CrossRefGoogle Scholar
Tanna, H. K., Dean, P. T. & Burrin, R. H. 1976 The generation and radiation of supersonic jet noise, vol. 3, Turbulent Mixing Noise Data. Air Force Aero-Propulsion Laboratory Report AFAPL-TR-65.Google Scholar
Viswanathan, K. 2004 Aeroacoustics of hot jets. J. Fluid Mech. 516, 39–82.CrossRefGoogle Scholar
Viswanathan, K. 2006 Scaling laws and a method for identifying components of jet noise. AIAA J. 44, 2274–2285.CrossRefGoogle Scholar
Viswanathan, K. & Clark, L. T. 2004 Effect of nozzle internal contour on jet aeroacoustics. Intl J. Aeroacoust. 3, 103–135.CrossRefGoogle Scholar
White, F. M. 1973 Viscous Fluid Flow. McGraw-Hill.Google Scholar