Numerical sensitivity analysis of reactive perforated muffler using factorial design method

摘要

Reactive perforated muffler reflects the sound waves back towards the source and prevent sound from being transmitted along the pipe due to its geometry inside. It is commonly used to reduce noise in ducts or pipes of mechanical systems, especially in the automotive industry. In a perforated muffler design problem, interior rigid partitions and holes should be dimensioned optimally to improve its acoustical attenuation performance in the frequency range of interest. In this paper a sensitivity analysis using a factorial design of the design variables was conducted in order to investigate the influence of the geometric parameters of the silencer in its acoustic performance – Transmission Loss (TL). The acoustic system was modeled and solved numerically with the Finite Element Method (FEM) in order to obtain the acoustic pressure. The numeric TL was estimated using the Three-points Method. The results demonstrated that the evaluated design parameters influence TL significantly, causing variations up to 35.5 dB