sonic boom propagation codes validated by flight test ?· sonic boom propagation codes validated...

Download Sonic Boom Propagation Codes Validated by Flight Test ?· Sonic Boom Propagation Codes Validated by…

Post on 27-Jul-2018

213 views

Category:

Documents

0 download

Embed Size (px)

TRANSCRIPT

  • NASA Contractor Report 201634

    Sonic Boom Propagation Codes Validatedby Flight Test

    Hugh W. Poling

    Boeing Commercial Airplane Group, Seattle, Washington

    Contract NAS 1-20220

    October 1996

    National Aeronautics and

    Space AdministrationLangley Research Center

    Hampton, Virginia 23681-0001

    https://ntrs.nasa.gov/search.jsp?R=19970011188 2018-07-27T11:47:45+00:00Z

  • Foreword

    The verification of sonic boom propagation codes has long been the desire of GeorgeT. Haglund. Working on supersonic transports virtually from their conception, hedeveloped many of the sonic boom analysis tools used at Boeing. He spearheadedinitial assessment of sonic boom characteristics of low-boom concepts at Boeing andoriginally proposed the idea of flying two aircraft in tandem to generate a shaped,long duration sonic boom source. Such a signature would require a very long

    propagation distance to completely evolve into an N-wave and thus provide the idealsource to test propagation codes for their resolution of fine detail in the sonic boomwaveform. Recent near-field pressure signature measurement of a single supersonicaircraft using a novel probing technique lays a foundation for such propagation codeverification and ultimate demonstration of the viability of low-boom supersonic

    transport design.

  • Contents

    Foreword ...........................................................

    Contents ............................................................

    List of Figures in Text ..............................................

    List of Figures in Appendices .......................................

    S_ary oeoeooooeeooeooooeeeoeoeoeeooeooooooeoooeeoeeoe ee oeeoeeoooo

    Propagation Codes

    Comparison to Measurement ...........................................

    Introduction ........................................................

    Absorption ...........................................................

    Code Development

    SHOCKN Code ......................................................

    Summary ............................................................

    Atmosphere Model ....................................................

    Sample Case .........................................................

    Outputs .............................................................

    ZEPHYRUS Code ...................................................

    Summary ............................................................

    Atmosphere Mode/ ....................................................

    Sample Case .........................................................

    Outputs .............................................................

    Comparison of SHOCKN and ZEPHYRUS ..........................

    Introduction .........................................................

    Impact of Standard Atmosphere ........................................

    Comparison Results ...................................................

    Comparison to Experiment .........................................

    SR71 Flight Test Summary ............................................

    Weather Conditions ...................................................

    Selected Flight Conditions .............................................

    Derivation of Measured Waveforms for Extrapolation .....................

    Analytic Propagation ..................................................

    Comparison of Measured and Analytic Waveforms ........................

    Noise Metrics ........................................................

    Conclusions ........................................................

    Propagation Codes ....................................................

    Comparison to Measurement ...........................................

    i

    iii

    V

    vi

    1

    1

    1

    2

    2

    2

    4

    4

    4

    5

    6

    8

    8

    8

    9

    14

    16

    16

    17

    18

    20

    20

    20

    22

    23

    25

    27

    32

    36

    36

    36

    iii

  • Contents (Concluded)

    pendix A-71 Measured Pressure Signatures and Flight Conditions ....... 37

    Appendix BSignature Time Histories for Extrapolation ........................ 53

    Appendix CWaveform Evolution ................................................ 63

    Appendix DCalculation of Perceived Level ..................................... 67

    References ......................................................... 68

    iv

  • List of Figures in Text

    Figure 1 Source Waveform for sample case .............................. 16

    Figure 2Ground Signatures for sample case for three different atmospheres ........ 17

    Figure 3Ground Signatures for sample case propagated with SHOCKN & ZEPHYRUS 18

    Figure 4Noise Spectra for sample case propagated with SHOCKN and ZEPHYRUS .

    Figure 5

    Figure 6Selection

    Figure 7

    Figure 8

    Figure 9

    Figure 10

    Figure 11

    Figure 12

    Figure 13

    Figure 14

    Figure 15

    Figure 16

    Figure 17

    Figure 18

    Figure 19

    Figure 20

    Figure 21

    Flight Conditions for SR-71 Flight Test .......................

    19

    22

    of "Near" and "Far" Measurements for ZEPHYRUS propagation . 23

    Measured Signature Durations ................................ 24

    Propagation Parameters for ZEPHYRUS ....................... 25

    Time History for Measurements #3 and #11 ................... 28

    Time History for Measurements #15 and #19 .................. 28

    Time History for Measurements #1 and #10 ................... 29

    Time History for Measurements #6 and #10 ................... 29

    Time History for Measurements #16 and #10 .................. 30

    Time History for Measurements #17 and #10 .................. 30

    Extrapolated Signature Characteristics ........................ 32

    Spectra for Measurements #3 and #11 ......................... 33

    Spectra for Measurements #15 and #19 ....................... 33

    Spectra for Measurements #1 and #10 ......................... 34

    Spectra for Measurements #1 and #6 .......................... 34

    Spectra for Measurements #1 and #16 ......................... 35

    Spectra for Measurements #1 and #17 ......................... 35

    V

  • Figure A.22

    Figure A.23

    Figure A.24

    Figure A.25

    Figure A.26

    Figure A.27

    Figure A.28

    Figure A.29

    Figure _4.30

    Figure A.31

    Figure A.32

    Figure A.33

    Figure A.34

    Figure A.35

    Figure A.36

    Figure B.1

    Figure B.2

    Figure B.3

    Figure B.4

    Figure B.5

    Figure B.6

    Figure B.7

    Figure B.8

    Figure B.9

    Figure C.1

    Figure C.2

    Figure C.3

    Figure C.4

    Figure C.5

    Figure C.6

    List of Figures in Appendices

    Measurement

    Measurement

    Measurement

    Measurement

    Measurement

    Measurement

    Measurement

    Measurement

    Measurement

    Measurement

    Number i of SR-71 Flight 24 ....................

    Number 2 of SR-71 Flight 24 ....................

    Number 3 of SR-71 Flight 24 ....................

    Number 4 of SR-71 Flight 24 ....................

    Number 5 of SR-71 Flight 24 ....................

    Number 6 of SR-71 Flight 24 ....................

    Number 7 of SR-71 Flight 24 ....................

    Number 8 of SR-71 Flight 24 ....................

    Number 10 of SR-71 Flight 24 ..................

    Number 11 of SR-71 Flight 24 ..................

    Measurement Number 14 of SR-71 Flight 24 ..................

    Measurement Number 15 of SR-71 Flight 24 ..................

    Measurement Number 16 of SR-71 Flight 24 ..................

    Measurement

    Measurement

    Time History

    Time History

    Time History

    Time History

    Time History

    Time History

    Time History

    Time History

    Time History

    Extrapolation

    Extrapolation

    Extrapolation

    Extrapolation

    Extrapolation

    Extrapolation

    Number 17 of SR-71 Flight 24 ..................

    Number 19 of SR-71 Flight 24 ..................

    for Measurement Number 1 of SR- 71 Flight 24 ....

    for Measurement Number 3 of SR-71 Flight 24 ....

    for Measurement Number 6 of SR-71 Flight 24 ....

    for Measurement Number 10 of SR-71 Flight 24...

    for Measurement Number 11 of SR-71 Flight 24...

    for Measurement Number 15 of SR-71 Flight 24...

    for Measurement Number 16 of SR-71 Flight 24 ...

    for Measurement Number 17 of SR-71 Flight 24 ...

    for Measurement Number 19 of SR-71 Flight 24...

    of Measurement Number 1 of SR-71 Flight 24 ....

    of Measurement Number 3 of SR-71 Flight 24 ....

    of Measurement Number 6 of SR-71 Flight 24 ....

    of Measurement Number 15 of SR-71 Flight 24 ...

    of Measurement Number 16 of SR-71 Flight 24 ...

    of Measurement Number 17 of SR-71 Flight 24 ...

    vi

    38

    39

    40

    41

    42

    43

    44

    45

    46

    47

    48

    49

    50

    51

    52

    54

    55

    56

    56

    58

    59

    60

    61

    62

    63

    64

    65

    65

    66

    66

  • Summary

    Propagation Codes

    A major thrust of recent developments to sonic boom propagation codes has been tomore properly incorporate air absorption effects. This effort has been made practicalby the general availability of improved computing power since absorption effects arebased on inclusion of "higher order" terms in the basic thermod

Recommended

View more >