This paper investigates the noise transmission performance of industrial mufflers widely used in ships based on the CAE modeling and simulation. Since the industrial mufflers have very complicated internal structures, the conventional Transfer Matrix Method (TMM) is of limited use. The CAE modeling and simulation is therefore required to incorporate commercial softwares: CATIA for geometry modeling, MSC/PATRAN for FE meshing and LMS/ SYSNOISE for analysis. Main sources of difficulties in this study are led by complicated arrangement of reactive elements, perforated walls and absorption materials. The reactive elements and absorbent materials are modeled by applying boundary conditions given by impedance. The perforated walls are modeled by applying the transfer impedance on the duplicated node mesh. The CAE approach presented in this paper is verified by comparing with the theoretical solution of a concentric-tube resonator and is applied for industrial mufflers.
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ASTM International 1998. ASTM E1050 Standard test method for impedance and absorption of acoustical materials using a tube two microphones and a digital frequency analysis system. West Conshohocken: ASTM International.
Bilawchuk S. and Fyfe K.R. 2003. Comparison and implementation of the various numerical methods used for calculating transmission loss in silencer system. Applied Acoustics 64(9) pp.903-916.
Dude P. and Sajanpawar P.R. 2007. Study of perforated mufflers of circular and elliptic cross sections using parametric technique and finite element methodology. SAE paper 2007-01-0895. Society of Automotive Engineers inc.: SAE International.
Gerges S.N.Y. Jordan R. Thieme F.A. Bento Coelho J.L. and Arenas J.P. 2005. Muffler modeling by transfer matrix method and experimental verification. Journal of the Brazilian Society of Mechanical Sciences and Engineering 27(2) pp.132-140.
Ju H.D. and Lee S.B. 2005. Transmission loss estimation of three dimensional silencers with perforated internal structures using multi-domain BEM. Journal of Mechanical Science and Technology 19(8) pp.1568-1575.
LMS.SYSNOISE rev 5.6 2003a. User manual: model data. Belgium: LMS International NV.
LMS.SYSNOISE rev 5.6 2003b. User manual: geometry modeling. Belgium: LMS International NV.
LMS.SYSNOISE rev 5.6 2003c. User manual: extracting information. Belgium: LMS International NV.
Munjal M.L. 1975. Velocity ratio-cum-transfer matrix method for the evaluation of a muffler with mean flow. Journal of Sound and Vibration 39(1) pp.105-119.
Munjal M. L. 1987. Acoustics of ducts and mufflers. New York: John Wiley & Sons.
Schultz T. Cattafesta L. and Sheplak M. 2006. Comparison of the two-microphone method and the modal decomposition method for acoustic impedance testing. Proceedings of the 12th AIAA/CEAS Aeroacoustics Conference Cambridge Massachusetts 8-10 May 2006 pp.3826-3838.
Soenark B. and Seybert A.F. 2000. Visualization of wave propagation in muffler. Journal of Visualization 3(3) pp.229-235.
Sullivan J.W. and Crocker M.J. 1978. Analysis of concentric-tube resonator having unpartitioned cavities. The Journal of the Acoustical Society of America 64(1) pp.207-215.