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Accession Number
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N20120010352
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Title
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Influence of Boundary Layer Parameters on Interior Noise.
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Publication Date
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May 2012
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Media Count
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13p
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Personal Author
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D. L. Palumbo J. Rocha
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Abstract
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Predictions of the wall pressure in the turbulent boundary of an aerospace vehicle can differ substantially from measurement due to phenomena that are not well understood. Characterizing the phenomena will require additional testing at considerable cost. Before expending scarce resources, it is desired to quantify the effect of the uncertainty in wall pressure predictions and measurements on structural response and acoustic radiation. A sensitivity analysis is performed on four parameters of the Corcos cross spectrum model: power spectrum, streamwise and cross stream coherence lengths and Mach number. It is found that at lower frequencies where high power levels and long coherence lengths exist, the radiated sound power prediction has up to 7 dB of uncertainty in power spectrum levels with streamwise and cross stream coherence lengths contributing equally to the total.
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Keywords
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Boundary layers
Mach number
Noise prediction
Power spectra
Sensitivity analysis
Sound waves
Spectra
Turbulence
Wall pressure
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Source Agency
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National Aeronautics and Space Administration
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NTIS Subject Category
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46A - Acoustics
46B - Fluid Mechanics
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Corporate Author
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National Aeronautics and Space Administration, Hampton, VA. Langley Research Center.
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Document Type
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Conference proceedings
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Title Note
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N/A
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NTIS Issue Number
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1226
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Contract Number
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N/A
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