Characteristics of Noise Attenuation with the Variation of Flow Condition and Hole Shape of Perforated Intruding Tues in Muffler

유동조건과 내부관 구명형상의 변화에 따른 소음기의 소음저감 특성

To propose a useful modelling method for an actual muffler, the noise attenuation effects of muffler was investigated according to the flow condition and the hole shape of tubes. In this work, the finite element method was used to calculate the transmission loss of muffler, The noise attenuation characteristics of four different types of muffler in the hole shape of tubes were compared mutually to find a more simple equivalent model. Analytical results showed that the overall value of transmission loss increases and the peaks of transmission loss curve shift to the low frequency with mean flow for the given muffler, Also the noise attenuation characteristics of the equivalent model having the split holes is almost the same as those of the actual muffler having many circular holes.