Wave propagation in a two-dimensional plane straight duct with panels embedded in its sidewalls

This paper presents analytical solutions of the problem of two-dimensional pressure wave propagation in a plane straight duct with rigid spring-supported wall panels. The problems of non-stationary and single-frequency pressure wave propagation in a semi-infinite duct with a moving piston and with panels locally embedded in the sidewalls are studied. Rigid panels are embedded in the sidewalls such that they can carry out small amplitude oscillations perpendicular to the main duct axis. The system of the duct with panels acts as a filter. Based on this filter property, which can be described by the panel parameters, a method of computing the acoustic pressure wave distribution in the duct is presented. A wave localisation effect in the duct caused by trapped modes has been found for particular parameters of the sidewall panels.