Accession Number N20120010352
Title Influence of Boundary Layer Parameters on Interior Noise.
Publication Date May 2012
Media Count 13p
Personal Author D. L. Palumbo J. Rocha
Abstract 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.
Keywords Boundary layers
Mach number
Noise prediction
Power spectra
Sensitivity analysis
Sound waves
Spectra
Turbulence
Wall pressure


 
Source Agency National Aeronautics and Space Administration
NTIS Subject Category 46A - Acoustics
46B - Fluid Mechanics
Corporate Author National Aeronautics and Space Administration, Hampton, VA. Langley Research Center.
Document Type Conference proceedings
Title Note N/A
NTIS Issue Number 1226
Contract Number N/A

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