BEM Formulation for axisymmetric acoustic problems

In this paper, I develop a boundary element method for axisymmetric acoustic radiation and propagation problems in a subsonic uniform flow. This formulation uses the axisymmetric convected Green's function independent of the flow direction arising from the adjunct operator by the Prandtl-Glauert transformation and uses two new operators, one concerning the particular normal derivative and the other concerning the convected normal derivative. These two new operators reduce the terms used in the conventional integral formulas developed in the literature, to facilitate the numerical and analytical method applied to the infinite axisymmetric cylindrical duct in a subsonic uniform flow.