A New Method for Determining Acoustic-liner Admittance in a Rectangular Duct with Grazing Flow from Experimental DataNational Aeronautics and Space Administration, Scientific and Technical Information Branch, 1984 - Acoustical engineering - 16 pages |
Common terms and phrases
acoustic pressure eigenfunction admittance Bw,u Admittance values determined analytical program axial propagation constant boundary conditions boundary-condition parameter Bw.l constant mean-flow profile continuity of acoustic-particle coordinate system cross-mode order determine the admittance DETERMINING ACOUSTIC-LINER ADMITTANCE dimensionless axial propagation duct with grazing eigenfunction F(y elimination is employed equa equation 14 equation 20 exact values expressed finite-element discretization first-order mode flows with two-dimensional form P(y,z functions F(y Gaussian elimination Global coordinate gradients grazing flow grazing-flow impedance tube hard-wall duct ikẞ input into equation K M(b Langley Research Center last row line element linear eigenvalue problem lower walls measured data method employed NASA nodes NÔN numerical method one-dimensional boundary layer ordinary differential equation paper Performing Organization rectangular duct row and column Runge-Kutta integration technique SHEAR FLOW solution to equation ßw,l ẞw,u stant third-order mode tion transverse directions unknown admittance value values of Bw wave number