Numerical Study of Acoustic Waves in a Non-Homogeneous Flow.

摘要

A numerical study of acoustic waves propagating in a non homogenous flow was performed on a two dimensional domain. A subsonic jet flow was used as a base flow to which an acoustic wave was superimposed. It was theoretically and numerically verified that the jet flow model that was used satisfied the Euler equations. In the numerical verification instabilities appeared the pressure and velocity fields. Since the instabilities were reflected at the outflow boundary and hence would destroy the calculations including acoustic waves, attempts were made to reduce the magnitude of the instabilities before they reached the outflow boundary. Examination of how many grid points that had to be used in order to propagate the acoustic wave in a non-homogenous medium was made.