Numerical and Acoustic Investigation of Muffler Internal Geometry on Exhaust Emission in Vehicles Using Abaqus

While mufflers are primarily designed for noise attenuation, their internal geometry profoundly influences exhaust flow characteristics and thermal behavior factors that indirectly impact vehicle emissions. This study explores the synergistic relationship between muffler design and emission control through coupled computational fluid dynamics and acoustic simulations. By analyzing diverse internal configurations including chambered, perforated, and helical geometries, we demonstrate how strategic flow path optimization can harmonize three critical objectives: backpressure reduction, acoustic damping, and thermal regulation near catalytic components. The simulations reveal that certain geometries inherently promote more uniform exhaust gas distribution, thereby stabilizing temperatures at the catalytic converter inlet and enhancing its pollutant conversion efficiency. Notably, designs incorporating graded porosity and segmented chambers exhibit inherent advantages in both noise suppression and flow conditioning, suggesting that mufflers could evolve from passive silencers into active contributors to emission control systems. These findings advocate for an integrated design philosophy where muffler development considers acoustic, thermal, and chemical performance metrics concurrently a paradigm shift with implications for urban air quality management and regulatory policy.

Keywords:

Muffler , exhaust emission , air pollution , numerical simulation , acoustic analysis