Finite element acoustic analysis of absorption silencers with mean flow

The acoustic performance of dissipative silencers, including the effects of both a mean flow in the airway and an induced internal steady flow in the absorbent, are analysed. Finite element models, based upon the modified Galerkin method, have been derived for the determination of the noise attenuation of silencers, both by forced response and eigenvalue analysis. The corresponding computer programs, incorporating subroutines from the NAG Finite Element library, have been developed. [Continues.]