Acoustical analysis, testing, and design of flow-reversing muffler chambers

Abstract

The transmission loss characteristics of flow-reversing muffler chambers were predicted by a numerical approach based on the finite element method. The theoretical model developed is described in this paper; its validity is established experimentally with a number of different chambers. The standing wave method was used to measure transmission loss and measurements were conducted with and without steady air flow. Depending on the inlet and outlet configurations, the flow-reversing chambers have two completely different transmission loss characteristics, one is similar to that for two sample expansion chambers in series and the other is similar to that for a side-branch resonator. Using the theoretical model developed, transmission loss curves were calculated for a large number of different flow-reversing chamber dimensions. Subject Classification: [43]50.30, [43]50.40.