TITLE
INVESTIGATION OF A MUFFLER WITH MODIFIED HELMHOLTZ RESONATOR VOLUME UNDER MULTI-LOAD OPERATING MODES
AUTHOR(S)
Hilmi Kuşçu1*, Tayfun Pektaş2
ABSTRACT
Helmholtz resonators are widely applied in exhaust aftertreatment systems to improve acoustic attenuation, but their performance depends on resonator volume and engine operating conditions. This study examines the effect of enlarging the resonator volume from 30.67 L to 57.83 L on the acoustic behavior of a prototype muffler. The objective was to evaluate transmission loss at multiple load points and provide a basis for future optimization. Acoustic measurements were performed under five operating modes, defined by engine speed and torque, with a microphone placed at the outlet. Results were benchmarked against a reference muffler. The modified design achieved notable improvements in insertion loss for four out of five modes, with relative gains up to 46%. Only at the lowest load condition (Mode 1) was a decrease observed. Back pressure remained within acceptable limits, indicating no major penalty in flow performance. Findings confirm that resonator volume has a strong influence on acoustic characteristics across operating conditions. While the prototype achieved substantial improvements, variations between modes emphasize the need for designs optimized for all load points. This work provides experimental evidence on the relationship between resonator volume and acoustic performance, serving as a foundation for future research in multi-load-point optimization.
DOI
How to cite this article:
Hilmi Kuşçu1*, Tayfun Pektaş2, INVESTIGATION OF A MUFFLER WITH MODIFIED HELMHOLTZ RESONATOR VOLUME UNDER MULTI-LOAD OPERATING MODES, UNITECH – SELECTED PAPERS - 2025