Experimental Validation of a Two-dimensional Shear-flow Model for Determining Acoustic ImpedanceNational Aeronautics and Space Administration, Scientif. and Techn. Information Branch, 1987 - 50 pages |
Common terms and phrases
3.0 Frequency 40 Axial distance Acoustic Impedance acoustic pressure profile admittance analytical model antiresonance attenuation and phase axial acoustic pressure axial propagation constant centerline Mach number coef Corr Data Least-square fit deg/cm downstream and upstream downstream propagation Duct Liners equation experimental flow duct flow Mach number flow profile grazing flow grazing-flow impedance data impedance measurements incidence impedance Intercept Slope Langley Research Center level attenuation profile linear least-square fit manometer math model MC/L Measured axial acoustic measured propagation constant NASA normal-incidence impedance Normalized acoustic null location number of 0.3 order mode phase profiles pressure level attenuation profile at Mach profile slopes propagation model propagation with error random measurement reactance reference location shear Sound pressure level standing wave ratios static pressure SWR and null systematic errors test frequencies test section test specimen tion total and static total pressure two-dimensional shear-flow model velocity profile