The noise generation mechanism of screech tone by shock leakage in underexpended round jets is experimentally investigated by means of phase-averaged velocity fields. Two jet flows at Mach numbers 1.10 and 1.15 are measured by a particle image velocimetry apparatus simultaneously with their near acoustic fields and sorted according to their phase with respect to a screech period. The coherent vorticity fields are then computed and analyzed. They depict two distinct regions of high level of vorticity fluctuations. Thanks to the knowledge about shock leakage gathered in previous studies, the role of both regions in the acoustic generation process is identified and a region of the flow is recognized as suitable for emitting acoustic waves. Phase-averaged schlieren visualizations are also computed and used to determine the motion of the first five shocks over a screech period. For both jets, the peak shock motion is found at the fourth shock tip. This shock is also located in the region recognized as favorable for the shock leakage to be observed.
PowellA.On edge tones and associated phenomena. Acustica1953;
3: 233–243.
2.
PowellA.On the mechanism of choked jet noise. Proc Phys Soc B1953;
66: 1039–1056.
3.
Massey KC and Ahuja KK. Screech frequency prediction in light of mode detection and convection speed measurements for heated jets. In: 3rd AIAA/CEAS Aeroacoustics Conference, 1997, Atlanta, GA, U.S.A., AIAA paper no. 97–1625.
GaoJHLiXD.A multi-mode screech frequency prediction formula for circular supersonic jets. J Acoust Soc Am2010;
127: 1251–1257.
6.
NagelRTDenhamJWPapathanasiouAG.Supersonic jet screech tone cancellation. AIAA J1983;
21: 1541–1545.
7.
Norum TD. Control of jet shock associated noise by a reflector. In: 9th Aeroacoustics Conference, 1984, Williamsburg, VA, U.S.A., AIAA paper no. 84–2279.
8.
Ahuja KK. Some unique experiments on receptivity. In: Shear Flow Control Conference, 1985, Boulder, CO, U.S.A., AIAA paper no. 85–0533.
9.
Raman G, Panda J and Zaman KBMQ. Feedback and receptivity during jet screech: influence of an upstream reflector. In: 35th Aerospace Sciences Meeting and Exhibit, 1997, Reno, NV, U.S.A., AIAA paper no. 97–0144.
10.
Harper-Bourne MJF. The noise from shock waves in supersonic jets. Noise mechanisms. In: AGARD Proceedings, 1974, Brussels, Belgium, paper no. CP 131.
11.
KweonYHTsuchidaMMiyazatoYet al.
The effect of reflector with sound-absorbing material on supersonic jet noise. J Therm Sci2005;
14: 22–27.
12.
TannaH.An experimental study of jet noise part i: turbulent mixing noise. J Sound Vib1977;
50: 405–428.
13.
NorumTDSeinerJM.Broadband shock noise from supersonic jets. AIAA J1982;
20: 68–73.
14.
Bridges JE and Wernet MP. Turbulence associated with broadband shock noise in hot jets. In: 14th AIAA/CEAS Aeroacoustics Conference, 2008, Vancouver, Canada, AIAA paper no. 2008–2834.
15.
AndréBCastelainTBaillyC.Broadband shock-associated noise in screeching and non-screeching underexpanded supersonic jets. AIAA J2013;
51: 665–673.
16.
TamCSeinerJYuJ.Proposed relationship between broadband shock associated noise and screech tones. J Sound Vib1986;
110: 309–321.
17.
TamCK.Supersonic jet noise. Annu Rev Fluid Mech1995;
27: 17–43.
18.
UmedaYIshiiR.On the sound sources of screech tones radiated from choked circular jets. J Acoust Soc Am2001;
110: 1845–1858.
19.
SuzukiTLeleSK.Shock leakage through an unsteady vortex-laden mixing layer: application to jet screech. J Fluid Mech2003;
490: 139–167.
20.
BerlandJBogeyCBaillyC.Numerical study of screech generation in a planar supersonic jet. Phys Fluids2007;
19: 075105.
21.
ShariffKManningTA.A ray tracing study of shock leakage in a model supersonic jet. Phys Fluids2013;
25: 076103.
22.
Edgington-MitchellDOberleithnerKHonneryDRet al.
Coherent structure and sound production in the helical mode of a screeching axisymmetric jet. J Fluid Mech2014;
748: 822–847.
23.
RamanG.Supersonic jet screech: half-century from Powell to the present. J Sound Vib1999;
225: 543–571.
AndréBCastelainTBaillyC.Experimental study of flight effects on slightly underexpanded supersonic jets. AIAA J2016;
55: 57–67.
26.
WestleyRWoolleyJ.The near field sound pressures of a choked jet during a screech cycle. Agard Cp1969;
42: 23-1–23-13.
27.
Panda J and Seasholtz R. Density measurement in underexpanded supersonic jets using Rayleigh scattering. In: 36th AIAA Aerospace Sciences Meeting and Exhibit, 1998, Reno, NV, U.S.A., paper no. 98–0281.
28.
AlkislarMBKrothapalliALourencoLM.Structure of a screeching rectangular jet: a stereoscopic particle image velocimetry study. J Fluid Mech2003;
489: 121–154.
29.
HendersonBBridgesJWernetM.An experimental study of the oscillatory flow structure of tone-producing supersonic impinging jets. J Fluid Mech2005;
542: 115–137.
30.
Seiner J and Norum T. Aerodynamic aspects of shock containing jet plumes. In: 6th Aeroacoustics Conference, 1980, Hartford, CT, U.S.A., AIAA paper no. 1980–965.
31.
WhiteF.Viscous fluid flow. McGraw-Hill International Edition.
New York, NY:
McGraw-Hill Higher Education, 2006. ISBN 9780071244930.
32.
KrothapalliAHsiaYBaganoffDet al.
The role of screech tones in mixing of an underexpanded rectangular jet. J Sound Vib1986;
106: 119–143.
33.
AndréBCastelainTBaillyC.Investigation of the mixing layer of underexpanded supersonic jets by particle image velocimetry. Int J Heat Fluid Flow2014;
50: 188–200.
34.
TanDJSoriaJHonneryDet al.
Novel method for investigating broadband velocity fluctuations in axisymmetric screeching jets. AIAA J2017;
55: 2321–2334.
35.
HussainAKMFZamanKBMQ.The free shear layer tone phenomenon and probe interference. J Fluid Mech1978;
87: 349–383.
36.
CrightonDG.Acoustics as a branch of fluid mechanics. J Fluid Mech1981;
106: 261–298.
37.
RamanGRiceEJ.Instability modes excited by natural screech tones in a supersonic rectangular jet. Phys Fluids1994;
6: 3999–4008.
38.
PandaJSeasholtzRG.Measurement of shock structure and shock-vortex interaction inunderexpanded jets using Rayleigh scattering. Phys Fluids1999;
11: 3761–3777.
39.
EckerTBrooksDRLoweKTet al.
Development and application of a point Doppler velocimeter featuring two-beam multiplexing for time-resolved measurements of high-speed flow. Exp Fluids2014;
55: 1819.
40.
MercierBCastelainTBaillyC.Experimental characterisation of the screech feedback loop in underexpanded round jets. J Fluid Mech2017;
824: 202–229.
41.
Edgington-Mitchell DM, Weightman JL, Honnery DR and Soria J. Sound production by shock leakage in supersonic jet screech. In: 2018 AIAA/CEAS Aeroacoustics Conference, Atlanta, GA, U.S.A., AIAA paper no. 2018–3147.
42.
WestleyRWoolleyJ. An investigation of the near noise fields of a choked axisymmetric air jet. Technical Report, National Aeronautical Establishment (Canada) Aero, 1968.
43.
Mercier B, Castelain T and Bailly C. A schlieren and nearfield acoustic based experimental investigation of screech noise sources. In: 22nd AIAA/CEAS Aeroacoustics Conference, 2016, Lyon, France, AIAA paper no. 2016–2799.
44.
Manning T and Lele S. A numerical investigation of sound generation in supersonic jet screech. In: 6th Aeroacoustics Conference and Exhibit, 2000, Lahaina, HI, U.S.A., AIAA paper no. 2000–2081.
45.
Lui C and Lele S. Sound generation mechanism of shock-associated noise. In: 9th AIAA/CEAS Aeroacoustics Conference and Exhibit, 2003, Hilton Head, SC, U.S.A., AIAA paper no. 2003–3315.
46.
Fujimatsu N and Misu I. Numerical investigation of sound generation in supersonic jet screech. In: 43rd Aerospace Sciences Meeting and Exhibit, 2005, Reno, NV, U.S.A., AIAA paper no. 2005–796.
47.
ShenHW TamCK.Three-dimensional numerical simulation of the jet screech phenomenon. AIAA J2002;
40: 33–41.
48.
TamCKParrishSAViswanathanK.Harmonics of jet screech tones. AIAA J2014;
52: 2471–2479.
49.
PowellAUmedaYIshiiR.Observations of the oscillation modes of choked circular jets. J Acoust Soc Am1992;
92: 2823–2836.
AndréBCastelainTBaillyC.Shock-tracking procedure for studying screech-induced oscillations. AIAA J2011;
49: 1563–1566.
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