Falcon 1 User's Guide - Rev 7 - FOIA and eLibrary website! - Nasa

Falcon 1 User’s Guide ‐ D000973 Rev. 7 Page | 29
3.4.4.4. ACOUSTIC ENVIRONMENT
During flight, the payload will be subjected to a varying acoustic environment. Levels are highest at lift off and
during transonic flight due to aerodynamic excitation. Falcon 1 will make use of acoustic blanketing to reduce the
acoustic environment and a nominal (minimal) 5 cm thick blanket configuration is assumed for the predicted
environment. Flight data were used to predict the worst‐case acoustic environment below. A summary of
acoustic MPE is shown in Table 3‐9 and plotted in Figure 3‐7.
TABLE 3‐9: FALCON 1 PAYLOAD ACOUSTIC ENVIRONMENT ASSUMING NOMINAL 5 CM ACOUSTIC BLANKETS
Frequency
(Hz)
Falcon 1 Payload
Acoustic MPE*
Frequency
(Hz)
20 103 500 122
25 106 630 122
31 109 800 122
40 112 1000 121
50 113.5 1250 120
63 115 1600 118
80 116 2000 117
100 117 2500 116
125 118 3150 115
160 119 4000 114
200 120 5000 113
250 121 6300 112
315 121.5 8000 111
400 122 10000 110
OASPL 132.6
*Empty Fairing (133 dB OASPL)
Falcon 1 Payload
Acoustic MPE*
140
130
120
SPL (dB, ref 20uPa)
110
100
90
Falcon 1 Payload Acoustic MPE - Empty Fairing (133 dB OASPL)
80
10 100 1000 10000
Frequency (Hz)
FIGURE 3‐7: SOUND PRESSURE LEVEL (SPL) SPECTRA FOR FALCON 1 ASSUMING 2 INCH ACOUSTIC BLANKETS
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