Abstract
Exhaust system plays an important role in defining NVH characteristics of a vehicle. In an Absorptive/Hybrid mufflers, glass-wool’s effectiveness is governed by its physical and mechanical properties; this paper focuses on the sensitivity analysis of above properties using CAE for improving the acoustic simulation and its correlation with Testing and subsequently establishing process for acoustical development of mufflers. The study of Porous material in an acoustic field is based on Biot theory. Biot parameters (porosity, flow resistivity, tortuosity, viscous characteristic length, and thermal characteristic length) and Sound absorption coefficient for different sound absorbing materials which are commonly used in the hybrid mufflers were tested and eventually a material database was generated. Thus a standard process was established for development of an efficient hybrid muffler for for future model developments