The identification of acoustic sources is critical to targeted noise reduction efforts for jets on high-performance tactical aircraft. This paper describes the imaging of acoustic sources from a tactical jet using near-field acoustical holography techniques. The measurement consists of a series of scans over the hologram with a dense microphone array. Partial field decomposition methods are performed to generate coherent holograms. Numerical extrapolation of data beyond the measurement aperture mitigates artifacts near the aperture edges. A multisource equivalent wave model is used that includes the effects of the ground reflection on the measurement. Multisource statistically optimized near-field acoustical holography (M-SONAH) is used to reconstruct apparent source distributions between 20 and 1250 Hz at four engine powers. It is shown that M-SONAH produces accurate field reconstructions for both inward and outward propagation in the region spanned by the physical hologram measurement. Reconstructions across the set of engine powers and frequencies suggests that directivity depends mainly on estimated source location; sources farther downstream radiate at a higher angle relative to the inlet axis. At some frequencies and engine powers, reconstructed fields exhibit multiple radiation lobes originating from overlapped source regions, which is a phenomenon relatively recently reported for full-scale jets.
References
1.
A.
Towne
, T.
Colonius
, P.
Jordan
, A.
Cavalieri
, and G. A.
Brès
, “Stochastic and nonlinear forcing of wavepackets in a Mach 0.9 jet
,” AIAA Paper 2015–2217 (2015
).2.
M.
Itasse
, J. P.
Brazier
, O.
Léon
, and G.
Casalis
, “Nonlinear interaction analysis of subsonic jet instabilities with forced eigenmodes using PSE
,” AIAA Paper
2015
–3124
(2015
).3.
J. D.
Maynard
, E. G.
Williams
, and Y.
Lee
, “Nearfield acoustic holography: 1. Theory of generalized holography and the development of NAH
,” J. Acoust. Soc. Am.
78
, 1395
–1413
(1985
).4.
E.
Mollo-Christensen
, “Jet noise and shear flow instability seen from an experimenter's viewpoint
,” J. Applied Mech.
34
, 1
–7
(1967
).5.
C. K. W.
Tam
, “Directional acoustic radiation froma supersonic jet generated by shear layer instability
,” J. Fluid Mech.
46
, 757
–768
(1971
).6.
C. K. W.
Tam
, “Mach wave radiation from high-speed jets
,” AIAA J.
47
, 2440
–2448
(2009
).7.
R. H.
Schlinker
, S. A.
Liljenberg
, D. R.
Polak
, K. A.
Post
, C. T.
Chipman
, and A. M.
Stern
, “Supersonic jet noise source characteristics and propagation: Engine and model scale
,” AIAA Paper 2007–3623 (2007
).8.
D. F.
Long
, “Jet noise source location via acoustic holography and shadowgraph imagery
,” AIAA Paper 2008–2888 (2008
).9.
D. F.
Long
, “Evaluation of jet and shock cell noise via acoustic holography
,” AIAA Paper 2008–5 (2008
).10.
S. S.
Lee
and J.
Bridges
, “Phased-array study of dual-flow jet noise: Effect of nozzles and mixers
,” AIAA Paper 2006-2647 (2006
).11.
A. T.
Wall
, K. L.
Gee
, M. M.
James
, K. A.
Bradley
, S. A.
McInerny
, and T. B.
Neilsen
, “Near-field noise measurements of a high-performance military jet aircraft
,” Noise Control Eng. J.
60
, 421
–434
(2012
).12.
B. M.
Harker
, K. L.
Gee
, T. B.
Neilsen
, A. T.
Wall
, and M. M.
James
, “Phased-array measurements of full-scale military jet noise
,” AIAA Paper 2014-3069 (2014
).13.
B. M.
Harker
, T. B.
Neilsen
, K. L.
Gee
, A. T.
Wall
, and M. M.
James
, “Spatiotemporal correlation analysis of jet noise from a high-performance military aircraft
,” AIAA Paper 2015-2376 (2015
).14.
D. M.
Hart
, T. B.
Neilsen
, K. L.
Gee
, and M. M.
James
, “A Bayesian based equivalent sound source model for a military jet aircraft
,” Proc. Mtg. Acoust.
19
, 055094
(2013
).15.
T. A.
Stout
, K. L.
Gee
, T. B.
Neilsen
, A. T.
Wall
, and M. M.
James
, “Intensity analysis of the dominant frequencies of military jet aircraft noise
,” Proc. Mtg. Acoust.
20
, 040010
(2015
).16.
T. B.
Neilsen
, K. L.
Gee
, A. T.
Wall
, and M. M.
James
, “Similarity spectra analysis of high-performance jet aircraft noise
,” J. Acoust. Soc. Am.
133
, 2116
–2125
(2013
).17.
D. F.
Long
, J.
Peters
, and M.
Anderson
, “Evaluating turbofan exhaust noise and source characteristics from near field measurements
,” AIAA Paper 2009-3214 (2009
).18.
P. N.
Shah
, H.
Vold
, and M.
Yang
, “Reconstruction of far-field noise using multireference acoustical holography measurements of high-speed jets
,” AIAA Paper 2011-2772 (2011
).19.
M.
Lee
and J. S.
Bolton
, “Source characterization of a subsonic jet by using near-field acoustical holography
,” J. Acoust. Soc. Am.
121
, 967
–977
(2007
).20.
H.
Vold
, P. N.
Shah
, J.
Davis
, P. G.
Bremner
, D.
McLaughlin
, P.
Morris
, J.
Veltin
, and R.
McKinley
, “High-resolution continuous scan acoustical holography applied to high-speed jet noise
,” AIAA Paper 2010-3754 (2010
).21.
A. T.
Wall
, K. L.
Gee
, T. B.
Neilsen
, D. W.
Krueger
, and M. M.
James
, “Cylindrical acoustical holography applied to full-scale jet noise
,” J. Acoust. Soc. Am.
136
, 1120
–1128
(2014
).22.
P.
Jordan
and T.
Colonius
, “Wave packets and turbulent jet noise
,” Annu. Rev. Fluid Mech.
45
, 173
–195
(2013
).23.
J.
Hald
, “STSF—a unique technique for scan-based near-field acoustic holography without restrictions on coherence
,” Brüel and Kjær Technical Review No. 1-1989 (1989
).24.
A. T.
Wall
, K. L.
Gee
, and T. B.
Neilsen
, “Multisource statistically optimized near-field acoustical holography
,” J. Acoust. Soc. Am.
137
, 963
–975
(2015
).25.
M.
Lee
and J. S.
Bolton
, “Scan-based near-field acoustical holography and partial field decomposition in the presence of noise and source level variation
,” J. Acoust. Soc. Am.
119
, 382
–393
(2006
).26.
S. M.
Price
and R. J.
Bernhard
, “Virtual coherence: A digital signal processing technique for incoherent source identification
,” in Proceedings of Fourth International Modal Analysis Conference
(1980
), pp. 1256
–1262
.27.
A. T.
Wall
, M. D.
Gardner
, K. L.
Gee
, and T. B.
Neilsen
, “Coherence length as a figure of merit in multireference near-field acoustical holography
,” J. Acoust. Soc. Am.
132
, EL215
–EL221
(2012
).28.
R.
Steiner
and J.
Hald
, “Near-field acoustical holography without the errors and limitations caused by the use of spatial DFT
,” Int. J. Acoust. Vib.
6
(2
), 83
–89
(2001
).29.
A. T.
Wall
, K. L.
Gee
, D. W.
Krueger
, T. B.
Neilsen
, S. D.
Sommerfeldt
, and M. M.
James
, “Aperture extension for near-field acoustical holography of jet noise
,” Proc. Mtg. Acoust.
14
, 065001
(2012
).30.
E. G.
Williams
, “Continuation of acoustic near-fields
,” J. Acoust. Soc. Am.
113
(3
), 1273
–1281
(2003
).31.
L. B.
Jackson
, Digital Filters and Signal Processing
, 2nd ed. (Kluwer Academic Publishers
, Boston
, 1989
), pp. 255
–257
.32.
H.
Vold
, P.
Shah
, P.
Morris
, Y.
Du
, and D.
Papamoschou
, “Axisymmetry and azimuthal modes in jet noise
,” AIAA Paper 2012-2214 (2012
).33.
A. T.
Wall
, K. L.
Gee
, and T. B.
Neilsen
, “Modified statistically optimized near-field acoustical holography for jet noise characterization
,” Proc. Mtg. Acoust.
19
, 055013
(2013
).34.
A. T.
Wall
, K. L.
Gee
, T. B.
Neilsen
, and M. M.
James
, “Acoustical holography imaging of full-scale jet noise fields
,” Proc. Noise-Con 2013
.35.
D. K.
McLaughlin
, C.-W.
Kuo
, and D.
Papamoschou
, “Experiments on the effect of ground reflections on supersonic jet noise
,” AIAA Paper 2008-22 (2008
).36.
Y. T.
Cho
, J. S.
Bolton
, and J.
Hald
, “Source visualization by using statistically optimized near-field acoustical holography in cylindrical coordinates
,” J. Acoust. Soc. Am.
118
(4
), 2355
–2364
(2005
).37.
J.
Hald
, “Basic theory and properties of statistically optimized near-field acoustical holography
,” J. Acoust. Soc. Am.
125
, 2105
–2120
(2009
).38.
J.
Morgan
, T. B.
Neilsen
, K. L.
Gee
, A. T.
Wall
, and M. M.
James
, “Simple-source model of military jet aircraft noise
,” Noise Control Engr. J.
60
(4
), 435
–449
(2012
).39.
E. G.
Williams
, “Regularization methods for near-field acoustical holography
,” J. Acoust. Soc. Am.
110
, 1976
–1988
(2001
).40.
R.
Reba
, S.
Narayanan
, and T.
Colonius
, “Wave-packet models for large-scale mixing noise
,” Int. J. Aeroacoust.
9
, 533
–558
(2010
).41.
A.
Sinha
, D.
Rodríguez
, G. A.
Brès
, and T.
Colonius
, “Wavepacket model for supersonic jet noise
,” J. Fluid Mech.
742
, 71
–95
(2014
).42.
D.
Papamoschou
, “Wavepacket modeling of the jet noise source
,” AIAA Paper 2011-2835 (2011
).43.
T. B.
Neilsen
, K. L.
Gee
, B. M.
Harker
, and M. M.
James
, in “Level-educed wavepacket representation of noise radiation from a high-performance military aircraft
,” AIAA Paper 2016-1880 (2016).44.
C. K. W.
Tam
and D. E.
Burton
, “Sound generated by instability waves of supersonic flows. Part 2. Axisymmetric jets
,” J. Fluid Mech.
138
, 273
–295
(1984
).45.
K. L.
Gee
, V. W.
Sparrow
, M. M.
James
, J. M.
Downing
, C. W.
Hobbs
, T. B.
Gabrielson
, and A. A.
Atchley
, “The role of nonlinear effects in the propagation of noise from high-power jet aircraft
,” J. Acoust. Soc. Am.
123
, 4082
–4093
(2008
).46.
C. E.
Tinney
, M. N.
Glauser
, and L. S.
Ukeiley
, “Low-dimensional characteristics of a transonic jet. Part 1. Proper orthogonal decomposition
,” J. Fluid Mech.
612
, 107
–141
(2008
).47.
B.
Greska
and A.
Krothapalli
, “On the far-field propagation of high-speed jet noise
,” in Proceedings of NCAD/NoiseCon2008
(2008
), No. NCAD2008-73071.48.
T. D.
Norum
, D. P.
Garber
, R. A.
Golub
, O. L.
Santa Maria
, and J. S.
Orme
, “Supersonic jet exhaust noise at high subsonic flight speed
,” NASA/TP-2004-212686 (2004
).49.
C. K. W.
Tam
and S. A.
Parrish
, “Noise of high-performance aircraft at afterburner
,” J. Sound Vib.
352
, 103
–208
(2015
).50.
J.
Liu
, A.
Corrigan
, K.
Kailasanath
, and E.
Gutmark
, “Impact of chevrons on noise source characteristics in imperfectly expanded jet flows
,” AIAA Paper 2015-2835 (2015
).51.
J.
Liu
, A.
Corrigan
, K.
Kailasanath
, and B.
Taylor
, “Impact of the specific heat ratio on noise generation in a high-temperature supersonic jet
,” AIAA Paper 2016-2125 (2016
).52.
A. T.
Wall
, K. L.
Gee
, T. B.
Neilsen
, B. M.
Harker
, S. A.
McInerny
, R. L.
McKinley
, and M. M.
James
, “Investigation of multi-lobed fighter jet noise sources using acoustical holography and partial field decomposition methods
,” AIAA Paper 2015-2379 (2015
).2016
U.S. Government
You do not currently have access to this content.