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Acoustics Research of Propulsion SystemsThe liftoff phase induces high acoustic loading over a broad frequency range for a launch vehicle. These external acoustic environments are used in the prediction of the internal vibration responses of the vehicle and components. Present liftoff vehicle acoustic environment prediction methods utilize stationary data from previously conducted hold-down tests to generate 1/3 octave band Sound Pressure Level (SPL) spectra. In an effort to update the accuracy and quality of liftoff acoustic loading predictions, non-stationary flight data from the Ares I-X were processed in PC-Signal in two flight phases: simulated hold-down and liftoff. In conjunction, the Prediction of Acoustic Vehicle Environments (PAVE) program was developed in MATLAB to allow for efficient predictions of sound pressure levels (SPLs) as a function of station number along the vehicle using semi-empirical methods. This consisted of generating the Dimensionless Spectrum Function (DSF) and Dimensionless Source Location (DSL) curves from the Ares I-X flight data. These are then used in the MATLAB program to generate the 1/3 octave band SPL spectra. Concluding results show major differences in SPLs between the hold-down test data and the processed Ares I-X flight data making the Ares I-X flight data more practical for future vehicle acoustic environment predictions.
Document ID
20140016707
Acquisition Source
Marshall Space Flight Center
Document Type
Conference Paper
Authors
Gao, Ximing
(NASA Marshall Space Flight Center Huntsville, AL, United States)
Houston, Janice
(NASA Marshall Space Flight Center Huntsville, AL, United States)
Date Acquired
November 26, 2014
Publication Date
October 27, 2014
Subject Category
Acoustics
Spacecraft Propulsion And Power
Launch Vehicles And Launch Operations
Report/Patent Number
M14-3917
Meeting Information
Meeting: Acoustical Society of America (ASA) Meeting
Location: Indianopolis, IN
Country: United States
Start Date: October 27, 2014
End Date: October 31, 2014
Sponsors: Acoustical Society of America
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
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