The acoustic waves propagation in a cylindrical waveguide with the laminar flow

The problem of modeling of acoustic wave propagation in inhomogeneous flow is considered. There is an approximate analytical solution of the hydrodynamics equations in the presence of annular acoustic oscillations source in the case of laminar flow. Special attention is to paid to the propagation of acoustic waves modes. The amplitudes and phases dependences of the individual modes on the Mach number in the linear approximation were established