Acoustic Theory of Axisymmetric Multisectioned Ducts |
Common terms and phrases
acoustic admittances acoustic field acoustic modes acoustic treatment admittance changes aircraft turbofan engine amplitude eq annular duct axisymmetric Beckemeyer boundary condition circular and annular circular duct continuity and momentum cylindrical coordinates dimensionless Dirac delta function duct section duct systems eigenfunction equation 25 equation 39a equation 69 equations 17 equations 42 equations are derived finite flange Green's function hard-walled identity matrix infinite duct Langley Research Center matrix equations matrix formulation matrix notation mean flow mode amplitudes momentum equations multisection liners muv mv orthogonal problem radiation directivity factors Radiation Impedances Radiation of Sound radiation reflection reflection coefficients reflection effects reflection equations reflection matrices shown in figure splitters submatrices subscripts and superscripts theory transmission and reflection unflanged duct uniform duct uniform flow uniform liner uniform multisectioned duct vector w+k-k wall admittance wave amplitudes wave equation Zorumski ικ ομ ομν