RT Journal Article ID 64141daf0176133b A1 Borisyuk, A. O. T1 Sound Generation by a Limited Region of Disturbed Flow in a Rigid Channel of Circular Cross-Section. A General Theory JF International Journal of Fluid Mechanics Research JO FMR YR 2004 FD 2005-02-01 VO 31 IS 3 OP 11 AB A general theory of sound generation by a limited region of disturbed flow in an infinite straight rigid-walled channel of circular cross-section is developed, and the quantitative relationships between the characteristics of the sound field generated and the parameters of the channel and flow are established. A disturbed flow is modeled by distributed quadrupole and dipole sources (which characteristics are assumed to be known), and the cases of uniform and non-uniform source distribution are considered. It is shown that the sound energy does not decrease as the distance from the sources increases, and it is equal to a sum of energies of the acoustic modes of the channel. The acoustic mode energy consists of three parts herewith. The first part is the energy generated by the volume quadrupoles, the second part results from the surface dipoles, and the third part is due to interaction of the quadrupoles and dipoles. An order of magnitude analysis of these parts is carried out for different values of the flow Mach number, and the corresponding simplified expressions for the acoustic power are obtained. PB Begell House LK https://www.dl.begellhouse.com/journals/71cb29ca5b40f8f8,7b34ca6043b7b7d4,64141daf0176133b.html