Acoustic scattering in a waveguide with a height discontinuity bridged by a membrane: a tailored Galerkin approach

This article is concerned with the reflection and the transmission of fluid–structure-coupled waves at the junction between two flexible waveguides of different heights. Unlike previous studies, in which the waveguides are joined at the height discontinuity by a rigid or soft strip, in this study, the height discontinuity is bridged by a membrane. The aims are first to develop a solution method that enables a wide range of conditions to be applied at the edges of the bridging membrane and then to ascertain the effects that these have on the reflected and the transmitted fields. Numerical results are presented which confirm that that the conditions applied at the edges of the bridging membrane do have significant effects on the reflected and the transmitted components of power.