The use of the finite-element method to calculate acoustic fields in inhomogeneous gas flows

Abstract

A numerical method for calculating linear acoustic fields in axisymmetric regions containing a subsonic irrotational gas flow is developed. The boundaries of the regions under consideration can contain portions corresponding to open space. The calculation scheme is based on the finite-element method, with the use of the variational principle. The time-averaged stationary parameters of the gas flow, necessary to calculate the acoustic fields excited in it, are found by solving the non-linear equations of gas dynamics using an iterative procedure similar to Newton's method.