MULTIPASS PERFORATED TUBE SILENCERS - A COMPUTATIONAL APPROACH

A time domain computational approach is applied to predict the acousti c performance of multiple pass silencers with perforated tube sections . This non-linear, one-dimensional method may readily include temporal and spatial variations in sound pressure level, orifice flow velociti es, and mean duct flow, all of which affect the local orifice behaviou r of perforated tube elements, and therefore the overall noise reducti on characteristics. The transmission loss of two anechoically terminat ed multiple pass muffler configurations is determined computationally and experimentally for the limiting case of low sound pressure levels and zero mean flow. Comparisons between the numerical results and expe rimental data are shown to correlate well for frequencies where the on e-dimensional assumption is justified. (C) 1998 Academic Press Limited .