Acoustic Modes in the Annular Duct with Uniform Mean Flow

Abstract

There are many benchmark problems in computational aeroacoustics (CAA) and acoustic mode in the annular duct with uniform mean flow is a problem of this kind. The energy relation of the duct mode is deduced from the governing equation, Euler equations in this paper. If the sound power level, angular frequency, azimuthal mode number and radial mode number are given, the acoustic mode in the annular duct can be expressed explicitly by the deduced results. The simulation of two different cases shows the propagation of a single acoustic mode in annular duct pictorially.