Skip to main content Accessibility help
×
Home

Linear and nonlinear mechanisms of sound radiation by instability waves in subsonic jets

  • VICTORIA SUPONITSKY (a1), NEIL D. SANDHAM (a1) and CHRISTOPHER L. MORFEY (a2)

Abstract

Linear and nonlinear mechanisms of sound generation in subsonic jets are investigated by numerical simulations of the compressible Navier–Stokes equations. The main goal is to demonstrate that low-frequency waves resulting from nonlinear interaction between primary, highly amplified, instability waves can be efficient sound radiators in subsonic jets. The current approach allows linear, weakly nonlinear and highly nonlinear mechanisms to be distinguished. It is demonstrated that low-frequency waves resulting from nonlinear interaction are more efficient in radiating sound when compared to linear instability waves radiating directly at the same frequencies. The results show that low-frequency sound radiated predominantly in the downstream direction and characterized by a broadband spectral peak near St = 0.2 can be observed in the simulations and described in terms of the nonlinear interaction model. It is also shown that coherent low-frequency sound radiated at higher angles to the jet axis (θ = 60°–707°) is likely to come from the interaction between two helical modes with azimuthal wavenumbers n = ±1. High-frequency noise in both downstream and side-line directions seems to originate from the breakdown of the jet into smaller structures.

Copyright

Corresponding author

Email address for correspondence: v.suponitsky@soton.ac.uk

References

Hide All
Cohen, J. & Wygnansky, I. 1987 The evolution of instabilities in the axisymmetric jet. Part 2. The flow resulting from interaction between two waves. J. Fluid Mech. 176, 221235.
Crighton, D. G. & Gaster, M. 1976 Stability of slowly diverging jet flow. J. Fluid Mech. 77, 397413.
Crighton, D. G. & Huerre, P. 1990 Shear layer pressure fluctuations and superdirective acoustic sources. J. Fluid Mech. 220, 355568.
Freund, J. B. 2001 Noise sources in a low-Reynolds-number turbulent jet at Mach 0.9. J. Fluid Mech. 438, 277305.
Gamard, S., Jung, D. & George, W. K. 2004 Downstream evolution of the most energetic modes in a turbulent axisymmetric jet at high Reynolds number. Part 2. The far-field region. J. Fluid Mech. 514, 205230.
Gaster, M., Kit, E. & Wygnanski, I. 1985 Large-scale structures in a forced turbulent mixing layer. J. Fluid Mech. 150, 2339.
Goldstein, M. E. 2001 An exact form of Lilley's equation with a velocity quadrupole/temperature dipole source term. J. Fluid Mech. 443, 231236.
Jones, L. E., Sandberg, R. D. & Sandham, N. D. 2008 Direct numerical simulations of forced and unforced separation bubbles on an airfoil at incidence. J. Fluid Mech. 602, 175207.
Laufer, J. & Yen, T. 1983 Noise generation by a low-Mach-number jet. J. Fluid Mech. 134, 131.
Moore, C. J. 1977 The role of shear-layer instability waves in jet exhaust noise. J. Fluid Mech. 80, 321367.
Ronneberger, D. & Ackermann, U. 1979 Experiments on sound radiation due to non-linear interaction of instability waves in a turbulent jet. J. Sound Vib. 62 (1), 121129.
Sandberg, R. D. & Sandham, N. D. 2006 Nonreflecting zonal characteristic boundary condition for direct numerical simulation of aerodynamic sound. AIAA J. 44 (2), 402405.
Sandberg, R. D., Sandham, N. D. & Joseph, P. F. 2007 Direct numerical simulations of trailing-edge noise generated by boundary-layer instabilities. J. Sound Vib. 304, 677690.
Sandham, N. D., Li, Q. & Yee, H. C. 2002 Entropy splitting for high-order numerical simulation of compressible turbulence. J. Comput. Phys. 178, 307322.
Sandham, N. D., Morfey, C. L. & Hu, Z. W. 2006 a Nonlinear mechanisms of sound generation in a perturbed parallel jet flow. J. Fluid Mech. 565, 123.
Sandham, N. D., Morfey, C. L. & Hu, Z. W. 2006 b Sound radiation from exponentially growing and decaying surface waves. J. Sound Vib. 294, 355361.
Sandham, N. D. & Salgado, A. M. 2008 Nonlinear interaction model of subsonic jet noise. Phil. Trans. R. Soc. A 366 (1876), 27452760.
Sandham, N. D., Salgado, A. M. & Agarwal, A. 2008 Jet noise from instability mode interactions. AIAA paper 2008-2987. 14th AIAA/CEAS Aeroacoustic Conference, Vancouver, Canada.
Sandhu, H. S. & Sandham, N. D. 1994 Boundary conditions for spatially growing compressible shear layers. Rep. QMW-EP-1100. Faculty of Engineering, Queen Mary and Westfield College, University of London.
Stromberg, J. L., McLaughlin, D. K. & Troutt, T. R. 1980 Flow field and acoustic properties of a Mach number 0.9 jet at a low Reynolds number. J. Fluid Mech. 72, 159176.
Suponitsky, V. & Sandham, N. D. 2009 Nonlinear mechanisms of sound radiation in a subsonic jet. AIAA paper 2009-3317. 15th AIAA/CEAS Aeroacoustic Conference, Miami, Florida, USA.
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. 2009 Mach wave radiation from high-speed jets. AIAA J. 47 (10), 24402448.
Tam, C. K. W. & Burton, D. E. 1984 Sound generated by instability waves of supersonic flows. Part 2. Axisymmetric jets. J. Fluid Mech. 138, 273295.
Tam, C. K. W. & Golebiowski, M. 1996 On the two components of turbulent mixing noise from supersonic jets. AIAA paper 96-1716. 2nd AIAA/CEAS Aeroacoustics Conference, State College, PA.
Tam, C. K. W. & Morris, P. J. 1980 The radiation of sound by the instability waves on a compressible plane turbulent shear layer. J. Fluid Mech. 99, 349381.
Tam, C. K. W., Viswanathan, K., Ahuja, K. K. & Panda, J. 2008 The sources of jet noise: experimental evidence. J. Fluid Mech. 615, 253292.
Thompson, K. W. 1987 Time dependent boundary conditions for hyperbolic systems. J. Comput. Phys. 68, 124.
Viswanathan, K. 2004 Aeroacoustics of hot jets. J. Fluid Mech. 516 (2), 3982.
Viswanathan, K. 2008 Investigation of noise source mechanisms in subsonic jets. AIAA J. 46 (8), 20202032.
Wu, X. 2005 Mach wave radiation of nonlinearly evolving supersonic instability modes in shear layers. J. Fluid Mech. 523, 121159.
Wu, X. & Huerre, P. 2009 Low-frequency sound radiated by a nonlinearly modulated wavepacket of helical modes on a subsonic circular jet. J. Fluid Mech. 637, 173211.
MathJax
MathJax is a JavaScript display engine for mathematics. For more information see http://www.mathjax.org.

JFM classification

Related content

Powered by UNSILO

Linear and nonlinear mechanisms of sound radiation by instability waves in subsonic jets

  • VICTORIA SUPONITSKY (a1), NEIL D. SANDHAM (a1) and CHRISTOPHER L. MORFEY (a2)

Metrics

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.