Sensitivity (mV/Pa)
100
10-1
10-2
10-3
102
103
104
Frequency (Hz)
Figure 16. The frequency response of the Endevco 8507-C2 pressure transducer as measured by
a GenRad model 1986 Omnical Sound Level Calibrator.
FIGURES
121
1.0
Spectral Power Density (Pa² / Hz)
0.1
0.01
0.001
0.0001
0.00001
10
100
1000
10000
100000
Frequency (Hz)
Figure 17. The spectral power density of the pressure transducer signal measured at x/L = 0.772,
N = 150° on a 6:1 prolate spheroid at " = 10° with only the static calibration applied.
FIGURES
122
10.0
Spectral Power Density (Pa² / Hz)
1.0
0.1
0.01
0.001
0.0001
0.00001
10
100
1000
10000
100000
Frequency (Hz)
Figure 18. The spectral power density of the pressure transducer signal measured at x/L = 0.772,
N = 150° on a 6:1 prolate spheroid at " = 10° with the static calibration and the Helmholtz
resonator theoretical correction applied.
FIGURES
123
1.2
1.0
v+ 2
0.8
0.6
0.4
0.2
0.0
101
2
3
4 5
102
2
3
4 5
103
2
3
y+
Figure 19. Profile of the ''
v 2 / u2J Reynolds normal stress in body-surface coordinates at
x/L = 0.772, N = 150° on a 6:1 prolate spheroid at " = 10°. Data of Chesnakas and
Simpson (1997).
FIGURES
124
20
15
-5 log10 (w+ ) + 4.0
10 log10 |F +(w)|
10
-10 log10 (w +) + 0.6
5
-25 log10 (w +) + 5.0
0
-5
-10
-50 log10 (w+ ) - 8.0
-15
-20
0.001
0.01
0.1
1.0
10.0
w+
Figure 20. Curves fit to the p spectrum beneath a two-dimensional boundary layer with favorable
pressure gradient normalized using viscous scales. These curves fit the data of McGrath and
Simpson (1987).
FIGURES
125
1000.0
|pmeas / ptrue |2
100.0
10.0
Low frequency comparison with
McGrath and Simpson (1987)
1.0
unity
0.1
100
direct comparison
with McGrath and
Simpson
blend
1000
Frequency (Hz)
10000
100000
Figure 21. Construction of the approximate transfer function for the Endevco pressure
transducer mounted at x/L = 0.772, N = 150° on a 6:1 prolate spheroid at " = 10°.
FIGURES
126
1000.0
|pmeas / ptrue |2
100.0
10.0
1.0
0.1
100
1000
10000
100000
Frequency (Hz)
Figure 22. The transfer function used for the p spectrum at " = 10°, x/L = 0.772, N = 150° (solid
line, equation 43) and the approximate transfer function shown in figure 21 (dashed line).
FIGURES
127
15
10
ΦMEASURED / ΦTRUE (dB)
5
0
-5
-10
-15
-20
α = 10o, x/L = 0.600, φ = 140o
α = 10o, x/L = 0.600, φ = 90o
-25
-30
102
103
104
105
Frequency (Hz)
Figure 23. Representative transfer functions that bound the transfer functions that were used for
the p data at x/L = 0.600.
FIGURES
128
15
10
ΦMEASURED / ΦTRUE (dB)
5
0
-5
-10
-15
-20
α = 10o, x/L = 0.772, φ = 140o
α = 20o, x/L = 0.772, φ = 160o
-25
-30
102
103
104
105
Frequency (Hz)
Figure 24. Representative transfer functions that bound the transfer functions that were used for
the p data at x/L = 0.772.
FIGURES
129