Noise Suppression Characteristics of Peripherally Segmented Duct LinersNational Aeronautics and Space Administration, Scientific and Technical Information Branch, 1981 - Noise control - 39 pages |
Common terms and phrases
1.00 radial mode 50 R Figure 9 modes 9 radial acoustic energy acoustic field acoustic intensity acoustic liners acoustic pressure ADMITTANCE FOR PLANE-WAVE analysis 50 analysis Exact value attenuation axially segmented liners B₂ basis functions boundary conditions circumferential mode computed from solving Duct Liners ducts with peripherally EFFECT INCREASING NUMBER EIGENVALUES AT OPTIMUM eigenvalues computed EIGENVALUES OF PERIPHERALLY equation 12 Exact value 50 Exact value Figure Exact value Value Galerkin method Helmholtz equation higher-order modes integer Langley Research Center Laplace operator lined section liner Peripheral liner mode Exact solution multitude of standing NASA noise suppression number of peripheral number of strips Numerical solution computed OPTIMUM ADMITTANCE peripheral strips peripherally segmented liners PLANE-WAVE SOURCE QR algorithm Radial mode Exact Semi-infinite circular duct series expansion solution to transcendental solving equation 21 source pressure standing waves table XIV transcendental number transmission loss uniform liner value Value computed wave number ле