This study experimentally investigates the generation mechanism of a higher-angle lobe which is an acoustic field feature of a supersonic jet impinging on an inclined flat plate. The overall sound pressure level distribution and spectra, the conditional averages of near field schlieren movies, and the time-averaged wall pressure distribution were obtained for three cases of Mach 1.8 ideally expanded impinging jets with plate angles of 45°, 22.5°, and 10° to the jet downstream axis. In the 45° and 22.5° cases, a higher-angle lobe appears. The dominant acoustic waves in the higher-angle lobe are radiated from the source region that contains shock waves and are suggested to be correlated with large-scale turbulent structures. These results suggest that the higher-angle lobe is dominated by acoustic waves generated by the interaction between the shock waves and large-scale turbulent structures. This inference is supported by the fact that the near-field acoustic wave patterns are qualitatively reproduced by the interference of monopoles located near the shock waves in the 45° and 22.5° cases and that neither the shock wave nor the higher-angle lobe is observed in the 10° case.

1.
K. M.
Eldred
, “
Acoustic loads generated by the propulsion system
,”
Report No. SP-8072
(
NASA
,
Washington, DC
,
1971
).
2.
D.
Edgington-Mitchell
, “
Aeroacoustic resonance and self-excitation in screeching and impinging supersonic jets – A review
,”
Int. J. Aeroacoust.
18
,
118
188
(
2019
).
3.
M.
Akamine
,
Y.
Nakanishi
,
K.
Okamoto
,
S.
Teramoto
,
T.
Okunuki
, and
S.
Tsutsumi
, “
Acoustic phenomena from correctly expanded supersonic jet impinging on inclined plate
,”
AIAA J.
53
,
2061
2067
(
2015
).
4.
M.
Akamine
,
K.
Okamoto
,
K. L.
Gee
,
T. B.
Neilsen
,
S.
Teramoto
,
T.
Okunuki
, and
S.
Tsutsumi
, “
Effect of nozzle–plate distance on acoustic phenomena from supersonic impinging jet
,”
AIAA J.
56
,
1943
1952
(
2018
).
5.
C.
Brehm
,
J. A.
Housman
, and
C. C.
Kiris
, “
Noise generation mechanisms for a supersonic jet impinging on an inclined plate
,”
J. Fluid Mech.
797
,
802
850
(
2016
).
6.
T.
Nonomura
,
Y.
Goto
, and
K.
Fujii
, “
Aeroacoustic waves generated from a supersonic jet impinging on an inclined flat plate
,”
Int. J. Aeroacoust.
10
,
401
425
(
2011
).
7.
T.
Nonomura
,
H.
Honda
,
Y.
Nagata
,
M.
Yamamoto
,
S.
Morizawa
,
S.
Obayashi
, and
K.
Fujii
, “
Plate-angle effects on acoustic waves from supersonic jets impinging on inclined plates
,”
AIAA J.
54
,
816
827
(
2016
).
8.
S.
Tsutsumi
,
R.
Takaki
,
Y.
Nakanishi
,
K.
Okamoto
, and, and
S.
Teramoto
, “
Acoustic generation mechanism of a supersonic jet impinging on deflectors
,” in
52nd Aerospace Sciences Meeting
,
National Harbor, MD
(
January 13–17
,
2014
), AIAA Paper 2014-0882.
9.
T. J.
Worden
,
C.
Shih
, and
F. S.
Alvi
, “
Supersonic jet impingement on a model-scale jet blast deflector
,”
AIAA J.
55
,
2522
2536
(
2017
).
10.
C. K. W.
Tam
, “
Mach wave radiation from high-speed jets
,”
AIAA J.
47
,
2440
2448
(
2009
).
11.
K. R.
Meadows
, “
A study of fundamental shock noise mechanisms
,” Technical Publication No. TP-3605 (
NASA
,
Washington, DC
,
1997
).
12.
D.
Edgington-Mitchell
,
J.
Weightman
,
S.
Lock
,
R.
Kirby
,
V.
Nair
,
J.
Soria
, and
D.
Honnery
, “
The generation of screech tones by shock leakage
,” J. Fluid Mech.
908
,
A46
(
2020
).
13.
T.
Suzuki
and
S. K.
Lele
, “
Shock leakage through an unsteady vortex-laden mixing layer: Application to jet screech
,”
J. Fluid Mech.
490
,
139
167
(
2003
).
14.
P. J.
Lamont
and
B. L.
Hunt
, “
The impingement of underexpanded, axisymmetric jets on perpendicular and inclined flat plates
,”
J. Fluid Mech.
100
(
3
),
471
511
(
1980
).
15.
Y.
Nakai
,
N.
Fujimatsu
, and
K.
Fujii
, “
Experimental study of underexpanded supersonic jet impingement on an inclined flat plate
,”
AIAA J.
44
,
2691
2699
(
2006
).
16.
J. C.
Carling
and
B. L.
Hunt
, “
The near wall jet of a normally impinging, uniform, axisymmetric, supersonic jet
,”
J. Fluid Mech.
66
,
159
176
(
1974
).
17.
M.
Kurokawa
,
S.
Teramoto
, and
K.
Okamoto
, “
Acoustic wave generation from two-dimensional supersonic inviscid jet impinging on inclined plate
,”
AIAA J.
58
,
3436
3445
(
2020
).
18.
K. A.
Kurbatskii
,
B.
Guenthoer
,
V.
Golubev
,
A.
Lyrintzis
,
R. R.
Mankbadi
, and
E.
Osman
, “
Numerical prediction of an acoustic field of a supersonic jet impinging on a plate at different inclination angles
,” in
Proceedings of the 20th AIAA/CEAS Aeroacoustics Conference
,
Atlanta, GA
(
June 16–20
,
2014
), AIAA Paper 2014-3308.
19.
A.
Risborg
and
J.
Soria
, “
High-speed optical measurements of an underexpanded supersonic jet impinging on an inclined plate
,” in
Proceedings of the 28th International Congress on High-Speed Imaging and Photonics
,
Canberra, Australia
(
November 9–14
,
2008
).
20.
C. duP.
Donaldson
and
R. S.
Snedeker
, “
A study of free jet impingement. Part 1. Mean properties of free and impinging jets
,”
J. Fluid Mech.
45
,
281
319
(
1971
).
21.
T.
Nguyen
,
B.
Maher
, and
Y.
Hassan
, “
Flowfield characteristics of a supersonic jet impinging on an inclined surface
,”
AIAA J.
58
,
1240
1254
(
2020
).
22.
Y.
Nakanishi
, “
Experimental study on acoustics from a correctly-expanded jet impinging on an inclined flat plate
,” Ph.D. dissertation,
University of Tokyo
,
Tokyo, Japan
(
2013
).
23.
C. K. W.
Tam
,
M.
Golebiowski
, and
J. M.
Seiner
, “
On the two components of turbulent mixing noise from supersonic jets
,” in
Proceedings of the 2nd AIAA/CEAS Aeroacoustics Conference
,
State College, PA
(
May 6–8
,
1996
), AIAA Paper 96-1716.
24.
M.
Akamine
,
K.
Okamoto
,
S.
Teramoto
, and
S.
Tsutsumi
, “
Conditional sampling analysis of high-speed schlieren movies of Mach wave radiation in a supersonic jet
,”
J. Acoust. Soc. Am.
145
,
EL122
EL128
(
2019
).
25.
C. K. W.
Tam
,
K.
Viswanathan
,
K. K.
Ahuja
, and
J.
Panda
, “
The sources of jet noise: Experimental evidence
,”
J. Fluid Mech.
615
,
253
292
(
2008
).
26.
M.
Akamine
,
K.
Okamoto
,
S.
Teramoto
,
T.
Okunuki
, and
S.
Tsutsumi
, “
Conditional sampling analysis of acoustic phenomena from a supersonic jet impinging on an inclined flat plate
,”
Trans. Jpn. Soc. Aero. S Sci.
59
,
287
294
(
2016
).
You do not currently have access to this content.