A Time-Domain Approach for Multi-Pass Perforated Tube Silencers

A time-domain computational approach is applied to analyze the acoustic performance of multiple-pass silencers containing perforated tube sections. The nonlinear, one-dimensional method may readily include temporal and spatial variations in sound pressure level, orifice flow velocities, and mean duct flow, all of which affect the behavior of perforated tube elements. The transmission loss characteristics of two anechoically-terminated multiple pass muffler configurations are determined computationally and experimentally for the limiting case of low sound pressure levels and zero mean flow. Comparisons between the numerical results and experimental data are shown to correlate well for frequencies where the one-dimensional assumption is justified.