Skewness values for the pressure time derivative are greater at ground-based measurements near a tactical aircraft than they are at nearby off-ground locations. A possible explanation for this phenomenon is the occurrence of nonlinear, irregular shock reflections at the ground. Propagation angle, source location, and corresponding angle of incidence relative to the ground are estimated using a two-point cross correlation of windowed shock events. Nonlinear reflections are likely to occur based on the combination of angles of incidence and measured shock strengths and cause a pressure increase at the shock that is greater than twice the free-field pressure. The associated pressure increase at the shocks appears to enhance shock-related metrics at the ground compared to off-ground locations.

1.
R.
Fievet
,
C. E.
Tinney
,
W. J.
Baars
, and
M. F.
Hamilton
, “
Coalescence in the sound field of a laboratory-scale supersonic jet
,”
AIAA J.
54
(
1
),
254
265
(
2016
).
2.
P.
Mora
,
N.
Heeb
,
J.
Kastner
,
E. J.
Gutmark
, and
K.
Kailasanath
, “
Effect of heat on the pressure skewness and kurtosis in supersonic jets
,”
AIAA J.
52
(
4
),
777
787
(
2014
).
3.
B. O.
Reichman
,
K. L.
Gee
,
T. B.
Neilsen
, and
S. H.
Swift
, “
Acoustic shock formation in noise propagation during ground run-up operations of military aircraft
,” AIAA Paper 2017-4043, June (
2017
).
4.
M. M.
James
,
A. R.
Salton
,
J. M.
Downing
,
K. L.
Gee
,
T. B.
Neilsen
,
B. O.
Reichman
,
R. L.
McKinley
,
A. T.
Wall
, and
H. L.
Gallagher
, “
Acoustic emissions from F-35 aircraft during ground run-up
,” AIAA Paper 2015-2375 (
2015
).
5.
K. L.
Gee
,
V. W.
Sparrow
,
M. M.
James
,
J. M.
Downing
,
C. M.
Hobs
,
T. B.
Gabrielson
, and
A. A.
Atchley
, “
The role of nonlinear effects in the propagation of noise from high power aircraft
,”
J. Acoust. Soc. Am.
123
(
6
),
4082
4093
(
2008
).
6.
S. H.
Swift
,
K. L.
Gee
, and
T. B.
Neilsen
, “
Testing two crackle criteria using modified jet noise waveforms
,”
J. Acoust. Soc. Am.
141
(
6
),
EL549
EL554
(
2017
).
7.
J. E.
Ffowes Williams
,
J.
Simson
, and
V. J.
Virchis
, “
Crackle': An annoying component of jet noise
,”
J. Fluid Mech.
71
(
2
),
251
271
(
1975
).
8.
A.
Krothapalli
,
L.
Venkatakrishnan
, and
L.
Lourenco
, “
Crackle—A dominant component of supersonic jet mixing noise
,” AIAA Paper 2000-2024, June (
2000
).
9.
K. L.
Gee
,
P. B.
Russavage
,
T. B.
Neilsen
,
S. H.
Swift
, and
A. B.
Vaughn
, “
Subjective rating of the jet noise crackle percept
,”
J. Acoust. Soc. Am.
144
(
1
),
EL40
EL44
(
2018
).
10.
S. A.
McInerny
,
K. L.
Gee
,
J. M.
Downing
, and
M. M.
James
, “
Acoustical nonlinearities in aircraft flyover data
,” AIAA Paper 2007-3654, May (
2007
).
11.
D. K.
McLaughlin
,
C. W.
Kuo
, and
D.
Papamoschou
, “
Experiments on the effect of ground reflections on supersonic jet noise
,” AIAA Paper 2008-22, January (
2008
).
12.
K. L.
Gee
,
T. B.
Neilsen
, and
M. M.
James
, “
Including source correlation and atmospheric turbulence in a ground reflection model for rocket noise
,”
Proc. Mtgs. Acoust.
22
(
1
),
1
17
(
2014
).
13.
S. A. E.
Miller
, “
The prediction of jet noise ground effects using an acoustic analogy and a tailored Green's function
,”
J. Sound Vib.
333
(
4
),
1193
1207
(
2014
).
14.
T. B.
Neilsen
,
A. B.
Vaughn
,
K. L.
Gee
,
S. H.
Swift
,
A. T.
Wall
,
J. M.
Downing
, and
M. M.
James
, “
Three-way spectral decompositions of high-performance military aircraft noise
,”
AIAA J.
57
(
8
),
3467
3479
(
2019
).
15.
B. M.
Harker
,
K. L.
Gee
,
T. B.
Neilsen
,
A. T.
Wall
, and
M. M.
James
, “
Source characterization of full-scale tactical jet noise from phased-array measurements
,”
J. Acoust. Soc. Am.
146
(
1
),
665
680
(
2019
).
16.
M. B.
Muhlestein
, “
Analyses of nonlinearity measures in high-amplitude sound propagation
,” Ph.D. dissertation,
Brigham Young University
,
Provo, UT
(
2013
), available at https://scholarsarchive.byu.edu/etd/3994 (Last viewed 1 July 2020) (see Fig. 6.9 for Sk{p/t}=4 at 48 kHz and p. 137 for peak Sk{p/t}=2.7 in the NAH plane).
17.
E.
Mach
, “
Uber den Verlauf von Funkenwellen in der Ebene und im Raume” (“Over the course of radio waves in the plane and in space”)
,
Sitzungsbr. Akad. Wiss. Wien
78
,
819
838
(
1878
).
18.
G.
Ben-dor
,
Shock Wave Reflection Phenomena
(
Springer
,
New York
,
2007
), pp.
3–4
and
297–303
.
19.
A. N.
Semenov
,
M. K.
Berezkina
, and
I. V.
Krassovskaya
, “
Classification of pseudo-steady shock wave reflection types
,”
Shock Waves
22
(
4
),
307
316
(
2012
).
20.
G.
Birkhoff
, “
Hydrodynamics: A study in logic, fact, and similitude
,”
Bull. Amer. Math. Soc.
57
,
97
499
(
1951
).
21.
P.
Colella
and
L. F.
Henderson
, “
The von Neumann paradox for the diffraction of weak shock waves
,”
J. Fluid Mech.
213
,
71
94
(
1990
).
22.
B. W.
Skews
and
J. T.
Ashworth
, “
The physical nature of weak shock wave reflection
,”
J. Fluid Mech.
542
,
105
114
(
2005
).
23.
J.
von Neumann
, “
Oblique reflection of shocks
,” in
John Von Neumann Collected Works
, edited by
A. H.
Taub
(
MacMillan
,
New York
,
1963
), Vol.
6
, pp.
238
299
.
24.
M. M.
Karzova
,
V. A.
Khokhlova
,
E.
Salze
,
S.
Ollivier
, and
P.
Blanc-Benon
, “
Mach stem formation in reflection and focusing of weak shock acoustic pulses
,”
J. Acoust. Soc. Am.
137
(
6
),
EL436
EL442
(
2015
).
25.
C.
Desjouy
,
S.
Ollivier
,
O.
Marsden
,
M. M.
Karzova
, and
P.
Blanc-Benon
, “
Irregular reflection of weak acoustic shock pulses on rigid boundaries: Schlieren experiments and direct numerical simulation on a Navier-Stokes solver
,”
Phys. Fluids
28
(
2
),
1
14
(
2016
).
26.
S.
Baskar
,
F.
Coulouvrat
, and
R.
Marchiano
, “
Nonlinear reflection of grazing acoustic shock waves: Unsteady transition from von Neumann to Mach to Snell-Descartes reflections
,”
J. Fluid Mech.
575
,
27
55
(
2007
).
27.
R.
Marchiano
,
F.
Coulouvrat
,
S.
Baskar
, and
J. L.
Thomas
, “
Experimental evidence of deviation from mirror reflection for acoustical shock waves
,”
Phys. Rev. E
76
(
5
),
1
5
(
2007
).
28.
M. M.
Karzova
,
T.
Lechat
,
S.
Ollivier
,
D.
Dragna
,
P. V.
Yuldashev
,
V. A.
Khokhlova
, and
P.
Blanc-Benon
, “
Effect of surface roughness on nonlinear reflection of weak shock waves
,”
J. Acoust. Soc. Am.
146
(
5
),
EL438
EL443
(
2019
).
29.
M.
Geva
,
O.
Ram
, and
O.
Sadot
, “
The non-stationary hysteresis phenomenon in shock wave reflections
,”
J. Fluid Mech.
732
,
R1
R11
(
2013
).
30.
T.
Suzuki
,
T.
Adachi
, and
S.
Kobayashi
, “
Experimental analysis of reflected shock behavior over a wedge with surface roughness
,”
JSME Int. J. Ser. B Fluids Therm. Eng.
36
(
1
),
130
134
(
1993
).
31.
E. A.
Zabolotskaya
and
V. R.
Khokhlov
, “
Quasi-plane waves in the nonlinear acoustics of confined beams
,”
Sov. Phys. Acoust.
15
,
35
40
(
1969
).
32.
K. M.
Leete
,
K. L.
Gee
,
T. B.
Neilsen
, and
T. T.
Truscott
, “
Mach stem formation in outdoor measurements of shocks
,”
J. Acoust. Soc. Am.
138
(
6
),
EL522
EL 527
(
2015
).
33.
A. B.
Vaughn
,
K. L.
Gee
,
S. H.
Hales
,
K. M.
Leete
,
A. T.
Wall
,
J. M.
Downing
, and
M. M.
James
, “
Source localization of crackle-related events in military aircraft jet noise
,”
AIAA J.
(published online
2021
).
34.
B. O.
Reichman
,
K. L.
Gee
,
T. B.
Neilsen
,
J. M.
Downing
,
M. M.
James
,
A. T.
Wall
, and
S. A.
McInerny
, “
Characterizing acoustic shocks in high-performance jet aircraft flyover noise
,”
J. Acoust. Soc. Am.
143
(
3
),
1355
1365
(
2018
).
35.
M. M.
Karzova
,
T.
Lechat
,
S.
Ollivier
,
D.
Dragna
,
P. V.
Yuldashev
,
V. A.
Khokhlova
, and
P.
Blanc-Benon
, “
Irregular reflection of spark-generated shock pulses from a rigid surface: Mach-Zehnder interferometry measurements in air
,”
J. Acoust. Soc. Am.
145
(
1
),
26
35
(
2019
).
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