Numerical Investigation of Acoustic Performance for Absorptive Exhaust Muffler

One of the significant environmental pollutants that may impact human health is noise. Meanwhile, modern engines are being increased in varied applications; their noise has become a serious problem. Recently, mufflers have attracted considerable attention for their role in reducing exhaust engine noise. This paper investigates the acoustic performance of an absorptive muffler with varied configurations to identify the most effective noise reduction model. A three-dimensional model has been built using COMSOL Multiphysics, and sound transmission loss was analyzed through numerical simulations based on FEM. The proposed model is validated against a model from the literature, showing strong agreement. Simulation is conducted for diverse muffler liner materials, liner thickness, and chamber diameter. Results indicate that the sound transmission loss depends on material air flow resistivity (Rf); better attenuation can be obtained with material of high Rf. Additionally, reducing the muffler diameter is more efficient.