A Method for Determining Acoustic-liner Admittance in Ducts with Sheared Flow in Two-cross-sectional Directions1985 - 40 pages |
Common terms and phrases
0.5i Exact admittance acoustic admittance acoustic field acoustic pressure Admittance from finite-element aeroacoustic Analysis 1.0 axial propagation constant Beckemeyer boundary conditions governing boundary layer boundary value problem centerline Mach number coefficient matrices coordinate system Determining Acoustic-Liner Admittance eigenvalue problem results equa equation 18 equation 25 equation 30 equation and boundary Exact Value Excellent comparison f₁ Figure finite-element method flow impedance test flow impedance tube flow profile function F(y,z G₂(y governing the acoustic grazing flow impedance grazing-flow impedance tube impedance test laboratory integration Langley Research Center linear matrix mean-flow profile measurements N₂ NASA node normal particle velocity number of points numerical method ONE-DIMENSIONAL SHEARED FLOW parameters partial differential equation particle displacement sample calculation single cross-sectional direction solution to equation sound pressure level test specimen tion two-dimensional sheared flow uniform flow unknown admittance value upper wall eigenfunction value problem wall eigenfunction NY+1 wall pressure eigenfunction wave number z-direction